Device charging system, charging method, and power adapter

ABSTRACT

The present disclosure provides a charging system and method and a power adapter. The system includes: a battery; a first rectification unit, configured to output a voltage with a first pulsating waveform; a switch unit, configured to modulate the voltage with the first pulsating waveform; a transformer, configured to output a voltage with a second pulsating waveform according to the modulated voltage; a second rectification unit, configured to rectify the voltage with the second pulsating waveform to output a voltage with a third pulsating waveform; and a control unit, configured to output the control signal to the switch unit to decrease a length of a valley of the voltage with the third pulsating waveform such that a peak value of a voltage of the battery is sampled.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No.PCT/CN2017/070537 filed on Jan. 7, 2017, which claims priority toInternational Application No. PCT/CN2016/073679 filed Feb. 5, 2016 andclaims priority to Chinese Patent Application No. 201610600612.3 filedJul. 26, 2016. The disclosures of each of the foregoing applications arehereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to a device technical field,and more particularly, to a charging system, a charging method and apower adapter.

BACKGROUND

Nowadays, mobile devices such as smart phones are favored by more andmore consumers. However, the mobile device consumes large power energy,and needs to be charged frequently.

Typically, the mobile device is charged by a power adapter. The poweradapter generally includes a primary rectifier circuit, a primary filtercircuit, a transformer, a secondary rectifier circuit, a secondaryfilter circuit and a control circuit, such that the power adapterconverts the input alternating current of 220V into a stable and lowvoltage direct current (for example, 5V) suitable for requirements ofthe mobile device, and provides the direct current to a power managementdevice and a battery of the mobile device, thereby realizing chargingthe mobile device.

However, with the increasing of the power of the power adapter, forexample, from 5 W to larger power such as 10 W, 15 W, 25 W, it needsmore electronic elements capable of bearing large power and realizingbetter control for adaptation, which not only increases a size of thepower adapter, but also increases a production cost and manufacturedifficulty of the power adapter.

SUMMARY

Embodiments of the present disclosure provide a charging system. Thecharging system includes: a battery; a first rectification unit,configured to rectify an input alternating current and output a voltagewith a first pulsating waveform; a switch unit, configured to modulatethe voltage with the first pulsating waveform according to a controlsignal; a transformer, configured to output a voltage with a secondpulsating waveform according to the modulated voltage with the firstpulsating waveform; a second rectification unit, configured to rectifythe voltage with the second pulsating waveform to output a voltage witha third pulsating waveform, in which the voltage with the thirdpulsating waveform is configured to be applied to the battery forcharging the battery; and a control unit, coupled to the switch unit,and configured to output the control signal to the switch unit and toadjust a duty ratio of the control signal such that the voltage with thethird pulsating waveform meets a charging requirement of the battery.The control unit is configured to, during a process that the poweradaptor charges the battery by outputting the voltage with the thirdpulsating waveform to the battery, adjust the duty ratio of the controlsignal to decrease a length of a valley of the voltage with the thirdpulsating waveform such that a peak value of a voltage of the battery issampled.

Embodiments of the present disclosure provide a power adapter. The poweradapter includes: a first rectification unit, configured to rectify aninput alternating current and output a voltage with a first pulsatingwaveform; a switch unit, configured to modulate the voltage with thefirst pulsating waveform according to a control signal; a transformer,configured to output a voltage with a second pulsating waveformaccording to the modulated voltage with the first pulsating waveform; asecond rectification unit, configured to rectify the voltage with thesecond pulsating waveform to output a voltage with a third pulsatingwaveform, in which the voltage with the third pulsating waveform isconfigured to be applied to a battery in a device for charging thebattery of the device; and a control unit, coupled to the switch unit,and configured to output the control signal to the switch unit and toadjust a duty ratio of the control signal such that the voltage with thethird pulsating waveform meets a charging requirement. During a processthat the power adaptor charges the battery by outputting the voltagewith the third pulsating waveform to the battery, the control unit isfurther configured to adjust the duty ratio of the control signal todecrease a length of a valley of the voltage with the third pulsatingwaveform such that sample a peak value of a voltage of the battery issampled.

Embodiments of the present disclosure provide a charging method. Themethod includes: performing a first rectification on an inputalternating current to output a voltage with a first pulsating waveform;modulating the voltage with the first pulsating waveform; outputting avoltage with a second pulsating waveform according to the modulatedvoltage with the first pulsating waveform; performing a secondrectification on the voltage with the second pulsating waveform tooutput a voltage with a third pulsating waveform; applying the voltagewith the third pulsating waveform to a battery of a; adjusting a dutyratio of a control signal for modulating the voltage with the firstpulsating waveform such that the voltage with the third pulsatingwaveform meets a charging requirement; and during a process that thepower adaptor charges the battery by outputting the voltage with thethird pulsating waveform to the battery, decreasing a length of a valleyof the voltage of the third pulsating waveform by adjusting the dutyratio of the control signal for modulating the voltage with the firstpulsating waveform such that a peak value of a voltage of the battery issampled.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram illustrating a charging system using aflyback switching power supply according to an embodiment of the presentdisclosure;

FIG. 1B is a schematic diagram illustrating a charging system using aforward switching power supply according to an embodiment of the presentdisclosure;

FIG. 1C is a schematic diagram illustrating a charging system using apush-pull switching power supply according to an embodiment of thepresent disclosure;

FIG. 1D is a schematic diagram illustrating a charging system using ahalf-bridge switching power supply according to an embodiment of thepresent disclosure;

FIG. 1E is a schematic diagram illustrating a charging system using afull-bridge switching power supply according to an embodiment of thepresent disclosure;

FIG. 2 is a block diagram of a charging system according to embodimentsof the present disclosure;

FIG. 3 is a schematic diagram illustrating a waveform of a chargingvoltage outputted to a battery from a power adapter according to anembodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating a waveform of a chargingcurrent outputted to a battery from a power adapter according to anembodiment of the present disclosure;

FIG. 5A is a schematic diagram illustrating a control signal outputtedto a switch unit according to an embodiment of the present disclosure;

FIG. 5B is a schematic diagram illustrating a comparison between a thirdpulsating waveform and an adjusted third pulsating waveform with adecreased length of a valley by adjusting a duty ratio of a controlsignal according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram illustrating a quick charging processaccording to an embodiment of the present disclosure;

FIG. 7A is a schematic diagram of a charging system according to anembodiment of the present disclosure;

FIG. 7B is a schematic diagram of a power adapter with a LC filtercircuit according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a charging system according to anotherembodiment of the present disclosure;

FIG. 9 is a schematic diagram of a charging system according to yetanother embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a charging system according to stillanother embodiment of the present disclosure;

FIG. 11 is a block diagram of a sampling unit according to an embodimentof the present disclosure;

FIG. 12 is a schematic diagram of a charging system according to stillyet another embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a device according to an embodiment ofthe present disclosure;

FIG. 14 is a schematic diagram of a device according to anotherembodiment of the present disclosure; and

FIG. 15 is a flow chart of a charging method according to embodiments ofthe present disclosure.

DETAILED DESCRIPTION

Descriptions will be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in drawings, in which thesame or similar elements and the elements having same or similarfunctions are denoted by like reference numerals throughout thedescriptions. The embodiments described herein with reference todrawings are explanatory, are intended to understand the presentdisclosure, and are not construed to limit the present disclosure.

The present disclosure is made based on following understanding andresearches.

The inventors found that, during charging a battery of a mobile deviceby a power adapter, as the power of the power adapter becomes larger, itis easy to increase polarization resistance and temperature of thebattery, thus reducing a service life of the battery, and affecting areliability and a safety of the battery.

Moreover, most devices cannot work directly with an alternating current(AC) when powered through an AC power supply, because the AC such asmains supply of 220V/50 Hz outputs electric energy discontinuously. Inorder to avoid such discontinuity, it needs to use an electrolyticcapacitor to store the electric energy, such that when the power supplyis in a valley period, it is possible to ensure the continuity of powersupply rely on the electric energy stored in the electrolytic capacitor.Thus, when an AC power source charges the mobile device via the poweradapter, the AC such as the AC of 220V provided by the AC power sourceis converted into a stable direct current (DC), and the stable DC isprovided to the mobile device. However, the power adapter charges thebattery in the mobile device so as to supply power to the mobile deviceindirectly, and the continuity of power supply can be guaranteed by thebattery, such that it is unnecessary for the power adapter to output astable and continue DC when charging the battery.

In addition, when the mobile device is charged by using a VOOC (VoltageOpen Loop Multi-step Constant-Current Charging) method with a lowvoltage and a high current in related arts, the power adaptor isdirectly coupled to the battery and an outputted voltage and current areadjusted by the power adaptor. Therefore, the power adaptor needs toacquire information, such as a voltage of the battery. The power adaptorjudges whether the acquired voltage of the battery reaches a targetvoltage. When the voltage of the battery reaches the target voltage, thepower adaptor starts to decrease the outputted current. However, theinformation, such as the voltage of the battery, is acquired through anADC (Analog to Digital Converter) and a sampled voltage isinstantaneous. In a case that the sampled voltage is instantaneous, itis feasible to use the sampled voltage in a DC charging process.However, in a pulsating charging process, there may be a problem.Because an inputted current is pulsating, and there is an internalresistor of the battery, the voltage of the battery fluctuates with afluctuation of waveforms of the pulsed current. Thus, the voltage of thebattery has a peak and a valley. In order to avoid an overvoltage of thebattery, it is necessary to ensure that a peak voltage of the battery isnot over-voltage. However, the sampled voltage is instantaneous byadopting the above-discussed method, and if the sampled voltage is thevalley, a real-time adjustment performed by the charging system may beaffected.

Before describing a charging system, a power adapter, a charging methodprovided in embodiments of the present disclosure, a power adapter thatis configured to charge a device to be charged (such as the device) inthe related art is described first, which is hereinafter referred to asa “related adapter”.

The related adapter is suitable for working in a constant voltage mode.In the constant voltage mode, a voltage outputted by the related adapteris basically constant, such as 5V, 9V, 12V or 20V, etc.

The voltage outputted by the related adapter is unsuitable for beingdirectly applied to two ends of a battery. It is required to convert thevoltage by a conversion circuit in the device to be charged (such as thedevice) to obtain a charging voltage and/or charging current expected bythe battery in the device to be charged (such as the device).

The conversion circuit is configured to convert the voltage outputted bythe related adapter, so as to meet requirements for the charging voltageand/or the charging current expected by the battery.

As an example, the conversion circuit may be a charging managementmodule, such as a charging integrated circuit (IC) in the device. Duringa process of charging the battery, the conversion circuit may beconfigured to manage the charging voltage and/or the charging current ofthe battery. The conversion circuit has functions of a voltage feedbackmodule and/or functions of a current feedback module, so as to realize amanagement on the charging voltage and/or the charging current of thebattery.

For example, the process of charging the battery may include at leastone of a trickle charging stage, a constant current charging stage and aconstant voltage charging stage. In the trickle charging stage, theconversion circuit may be configured to utilize a current feedback loopto ensure that a current flowing into the battery within the tricklecharging stage meets the charging current (such as a first chargingcurrent) expected by the battery. In the constant current chargingstage, the conversion circuit may be configured to utilize a currentfeedback loop to ensure that a current flowing into the battery withinthe constant current charging stage meets the charging current (such asa second charging current, which may be greater than the first chargingcurrent) expected by the battery. In the constant voltage chargingstage, the conversion circuit may be configured to utilize a voltagefeedback loop to ensure that a voltage applied to two ends of thebattery within the constant voltage charging stage meets the chargingvoltage expected by the battery.

As an example, when the voltage outputted by the related adapter isgreater than the charging voltage expected by the battery, theconversion circuit may be configured to perform buck conversion on thevoltage outputted by the related adapter, such that a buck-convertedvoltage meets the requirement of the charging voltage expected by thebattery. As another example, when the voltage outputted by the relatedadapter is less than the charging voltage expected by the battery, theconversion circuit may be configured to perform boost conversion on thevoltage outputted by the related adapter, such that a boost-convertedvoltage meets the requirement of the charging voltage expected by thebattery.

As another example, assume that the related adapter outputs a constantvoltage of 5V. When the battery includes a single battery cell (such asa lithium battery cell, a charging cut-off voltage of the single batterycell is 4.2V), the conversion circuit (for example, a buck circuit) mayperform the buck conversion on the voltage outputted by the relatedadapter, such that the charging voltage obtained after the buckconversion meets the requirement of the charging voltage expected by thebattery.

As yet another example, assume that the related adapter outputs aconstant voltage of 5V. When the related adapter charges a batteryincluding two or more battery cells (such as two or more lithium batterycells, a charging cut-off voltage of a single battery cell is 4.2V)coupled in series, the conversion circuit (for example, a boost circuit)may perform the boost conversion on the voltage outputted by the relatedadapter, such that the charging voltage obtained after the boostconversion meets the requirement of the charging voltage expected by thebattery.

Limited by poor conversion efficiency of the conversion circuit, anunconverted part of electric energy is dissipated in a form of heat, andthis part of heat may gather inside the device to be charged (such asthe device). A design space and a cooling space of the device to becharged (such as the device) are small (for example, a physical size ofa mobile device used by a user becomes thinner and thinner, while plentyof electronic components are densely arranged in the mobile device toimprove performance of the mobile device), which not only increasesdifficulty in designing the conversion circuit, but also results in thatit is hard to dissipate the heat gathered in the device to be charged(such as the device) in real time, thus further causing abnormity of thedevice to be charged (such as the device).

For example, heat gathered on the conversion circuit may cause thermalinterference on electronic components neighboring the conversioncircuit, thus causing abnormal operations of the electronic components;and/or for another example, heat gathered on the conversion circuit mayshorten service lifespan of the conversion circuit and neighboringelectronic components; and/or for yet another example, heat gathered onthe conversion circuit may cause thermal interference on the battery,thus causing abnormal charging and discharging of the battery; and/orfor still another example, heat gathered on the conversion circuit mayincrease temperature of the device to be charged (such as the device),thus affecting user experience during the charging; and/or for still yetanother example, heat gathered on the conversion circuit mayshort-circuit the conversion circuit, such that the voltage outputted bythe related adapter is directly applied to two ends of the battery, thuscausing over-voltage charging of the battery, which even brings safetyhazard, for example, the battery may explode, if the over-voltagecharging lasts for a long time period.

A power adapter provided in embodiments of the present disclosure mayobtain status information of the battery. The status information of thebattery may at least include electric quantity information and/orvoltage information of the battery. The power adapter may adjust thevoltage outputted by itself according to the obtained status informationof the battery, to meet the requirement of the charging voltage and/orthe charging current expected by the battery. Further, the outputvoltage of the power adapter after the adjustment may be directlyapplied to two ends of the battery for charging the battery. The outputvoltage of the power adapter is one with a pulsating waveform.

The power adapter may have functions of a voltage feedback module and/orfunctions of a current feedback module, so as to realize management onthe charging voltage and/or the charging current of the battery.

In some embodiments, the power adapter may adjust the voltage outputtedby the power adapter according to the obtained status information of thebattery as follows. The power adapter may obtain the status informationof the battery in real time, and adjust the voltage outputted by itselfaccording to the status information of the battery obtained in realtime, to meet the charging voltage and/or the charging current expectedby the battery.

The power adapter may adjust the voltage outputted by itself accordingto the status information of the battery obtained in real time asfollows. With the increasing of the charging voltage of the batteryduring the charging process, the power adapter may obtain statusinformation of the battery at different time points in the chargingprocess, and adjust the voltage outputted by itself in real timeaccording to the status information of the battery, to meet therequirement of the charging voltage and/or the charging current expectedby the battery. The output voltage of the power adapter after theadjustment may be directly applied to two ends of the battery forcharging the battery.

For example, the process of charging the battery may include at leastone of a trickle charging stage, a constant current charging stage and aconstant voltage charging stage. In the trickle charging stage, thepower adapter may be configured to output the first charging currentwithin the trickle charging stage to charge the battery, so as to meetthe requirement of the charging current expected by the battery (thefirst charging current may be one with a pulsating waveform). In theconstant current charging stage, the power adapter may be configured toutilize the current feedback loop to ensure that the current outputtedby the power adapter and flowing into the battery within the constantcurrent charging stage meets the requirement of the charging currentexpected by the battery (such as the second charging current, which alsomay be one with a pulsating waveform. The second charging current may begreater than the first charging current. That is, a current peak of thepulsating waveform in the constant current charging stage is greaterthan that in the trickle charge stage, and the constant current in theconstant current charging phase may refer to the current peak or acurrent average value of the pulsating waveform remains substantiallyconstant). In the constant voltage charging stage, the power adapter maybe configured to utilize the voltage feedback loop to ensure that thevoltage (the voltage with the pulsating waveform) outputted within theconstant voltage charging stage from the power adapter to the device tobe charged (such as the device) remains constant.

For example, the power adapter provided in embodiments of the presentdisclosure may be configured to control the constant current chargingstage of the battery within the device to be charged (such as thedevice) mainly. In other embodiments, a control function of the tricklecharging stage and the constant voltage charging stage of the batterywithin the device to be charged (such as the device) may be completedcollaboratively by the power adapter provided in embodiments of thepresent disclosure and an additional charging chip in the device to becharged (such as the device). Compared to the constant current chargingstage, a charging power acceptable by the battery during the tricklecharging stage and the constant voltage charging stage is small, andefficiency conversion loss and heat accumulation of the charging chipwithin the device to be charged (such as the device) is acceptable. Itis to be noted that, the constant current charging stage or the constantcurrent stage provided in embodiments of the present disclosure mayrefer to a charging mode for controlling the output current of the poweradapter and does not require that the output current of the poweradapter be kept completely constant, for example, it can be referred tothat the current peak or the current average value of the pulsatingwaveform outputted by the power adapter remain essentially unchanged, orremain basically unchanged for a period of time. For example, inpractice, the power adapter typically adopts a multi-stage constantcurrent mode for charging during the constant current charging mode.

The multi-stage constant current charging may include N charging stages,where N is an integer no less than 2. The first charging stage of themulti-stage constant current charging starts with a predeterminedcharging current. N constant charging stages in the multi-stage constantcurrent charging are performed in sequence from the first charging stageto the (N−1)^(th) charging stage. After the charging stage is switchedfrom one charging stage to a next charging stage, the current peak orthe current average value of the pulsating waveform may be decreased.When the voltage of the battery reaches a charging stop voltagethreshold, the charging stage is switched from the present chargingstage to the next charging stage. The current conversion process betweentwo adjacent constant stages may be gradual, or step-by-step.

Further, it is to be noted that, the device applied in embodiments ofthe present disclosure includes, but is not limited to a deviceconfigured to receive/transmit communication signals via wiredconnection (for example, public switched telephone network (PSTN),digital subscriber line (DSL), digital cable, a direct cable and/oranother data connection/network) and/or via a wireless interface (forexample, cellular network, wireless local area network (WLAN), digitalTV network such as digital video broadcasting handheld (DVB-H) network,satellite network, an amplitude modulation-frequency modulation (AM-FM)broadcasting transmitter, and/or a wireless interface of anothercommunication device). The communication device configured tocommunicate via the wireless interface may be referred to as “wirelesscommunication device”, “wireless device” and/or “mobile device”.Examples of the mobile device include, but are not limited to asatellite phone or a cell phone, a device combining a cell radio phoneand a personal communication system (PCS) having capability of dataprocess, fax, and data communication, a personal digital assistant (PDA)including a radio phone, a pager, an Internet/Intranet access, a webbrowser, a notepad & address book, a calendar and/or a globalpositioning system (GPS) receiver, and a common laptop and/or handheldreceiver, or other electronic device including a radio phonetransceiver.

In addition, in embodiments of the present disclosure, the voltage withthe pulsating waveform output from the power adapter is directly appliedto the battery of the device for charging the battery, and the chargingcurrent is represented by the pulsating waveform, for example, asteamed-bun shaped waveform. It is to be understood that, the chargingcurrent may charge the battery intermittently, and the cycle of thecharging current may vary with frequency of the input alternatingcurrent, such as power grid, for example, the frequency corresponding tothe cycle of the charging current may be an integral multiple or afraction of the frequency of the power grid. In addition, when thecharging current charges the battery intermittently, the currentwaveform corresponding to the charging current may consist of one pulseor one set of pulses synchronous to the power grid.

In the following, a charging system, a power adapter and a chargingmethod provided in embodiments of the present disclosure will bedescribed with reference to drawings.

Referring to FIGS. 1A-14 , the charging system provided in embodimentsof the present disclosure includes a power adapter 1 and a device 2.

As illustrated in FIG. 2 , the power adapter 1 includes a firstrectification unit 101, a switch unit 102, a transformer 103, a secondrectification unit 104, a sampling unit 106, and a control unit 107. Thefirst rectification unit 101 is configured to rectify an inputalternating current (mains supply, for example AC 220V) to output avoltage with a first pulsating waveform, for example a voltage with asteamed-bun shaped waveform. As illustrated in FIG. 1A, the firstrectification unit 101 may be a full-bridge rectifier circuit consistingof four diodes. The switch unit 102 is configured to modulate thevoltage with the first pulsating waveform according to a control signal.The switch unit 102 may consist of MOS transistors. A PWM (Pulse WidthModulation) control is performed on the MOS transistors to perform achopping modulation on the voltage with the steamed-bun shaped waveform.The transformer 103 is configured to output a voltage with a secondpulsating waveform according to the modulated voltage with the firstpulsating waveform. The second rectification unit 104 is configured torectify the voltage with the second pulsating waveform and output avoltage with a third pulsating waveform. The second rectification unit104 may consist of diodes or MOS transistors, and can realize asecondary synchronous rectification, such that the third pulsatingwaveform keeps synchronous with a waveform of the modulated voltage withthe first pulsating waveform. It should be noted that, the thirdpulsating waveform keeping synchronous with the waveform of themodulated voltage with the first pulsating waveform means that, a phaseof the third pulsating waveform is consistent with that of the waveformof the modulated voltage with the first pulsating waveform, and avariation trend of magnitude of the third pulsating waveform isconsistent with that of the waveform of the modulated voltage with thefirst pulsating waveform. The sampling unit 106 is configured to samplea voltage and/or a current outputted by the second rectification unit104 so as to obtain a voltage sampling value and/or a current samplingvalue. The control unit 107 is coupled to the sampling unit 106 and theswitch unit 102 respectively. The control unit 107 is configured tooutput the control signal to the switch unit 102 and to adjust a dutyratio of the control signal according to the current sampling valueand/or the voltage sampling value, such that the voltage with the thirdpulsating waveform outputted by the second rectification unit 104 meetsa charging requirement.

Further, in an embodiment of the present disclosure, the power adapterfurther includes a first charging interface 105. The first charginginterface 105 is coupled to the second rectification unit 104. The firstcharging interface 105 is configured to apply the voltage with the thirdpulsating waveform to the battery in the device via a second charginginterface of the device when the first charging interface 105 is coupledto the second charging interface, in which the second charging interfaceis coupled to the battery.

As illustrated in FIG. 2 , the device 2 includes a battery 202.

In an embodiment, the device 2 further includes a second charginginterface 201. The second charging interface 201 is coupled to thebattery 202. When the second charging interface 201 is coupled to thefirst charging interface 105, the second charging interface 201 isconfigured to apply the voltage with the third pulsating waveform to thebattery 202, so as to charge the battery 202.

Furthermore, the device includes a battery voltage sampling unit. Thebattery voltage sampling unit is configured to sample the voltage of thebattery. During a process that the power adaptor 1 charges the batteryby outputting the voltage with the third pulsating waveform, the controlunit 107 is configured to reduce a length of a valley of the voltagewith the third pulsating waveform by controlling the duty ratio of thecontrol signal, such that the battery voltage sampling unit isconfigured to sample a peak value of the voltage of the battery. Thebattery voltage sampling unit includes an electric meter. The voltage ofthe battery is sampled by the electric meter.

In other words, during the process that the power adapter charges thebattery by outputting the voltage with the third pulsating waveform, asthe battery is charged with pulsating waveforms, it may not guaranteethat the peak value of the voltage of the battery is sampled preciselyeach time through the battery voltage sampling unit. When the battery ischarged with the pulsating waveforms, if the charging current isstopped, the charging current does not drop to zero immediately, but isdecreased slowly. The shorter the stopped period, the less the change inthe charging voltage. Therefore, in embodiments of the presentdisclosure, the control unit 107 is configured to decrease the length ofthe valley of the voltage with the third pulsating waveform by adjustingthe duty ratio of the control signal, thereby reducing a voltagedifference between the peak value and the valley value of the voltage ofthe battery. Thus, the fluctuation of the voltage of the battery iseffectively reduced when the battery is charged with pulsatingwaveforms, which is contributed to sample the peak value of the voltageof the battery, thereby ensuring the safety and reliability of thecharging system. For example, as illustrated in FIG. 5B, a comparisonbetween a PWM signal without an adjustment and a PWM signal with theadjustment is illustrated. The control unit 107 is configured todecrease the length of the valley of the voltage with the thirdpulsating waveform by controlling the duty ratio of the control signal.The duty ratio of the PWM signal is adjusted as large as possible, thusthe length of the valley of the voltage with the third pulsatingwaveform is adjusted as less as possible. Therefore, the voltagedifference between the peak value and the valley value of the voltage ofthe battery is reduced, thus reducing the fluctuation of the voltage ofthe battery when the battery is charged with pulsating waveform, whichis contributed to sample the value peak of the voltage of the battery bythe battery voltage sampling unit.

In an embodiment of the present disclosure, as illustrated in FIG. 1A,the power adapter 1 may adopt a flyback switching power supply. Indetail, the transformer 103 includes a primary winding and a secondarywinding. An end of the primary winding is coupled to a first output endof the first rectification unit 101. A second output end of the firstrectification unit 101 is grounded. Another end of the primary windingis coupled to the switch unit 102 (for example, if the switch unit 102is a MOS transistor, the other end of the primary winding is coupled toa drain of the MOS transistor). The transformer 103 is configured tooutput a voltage with a second pulsating waveform according to themodulated voltage with the first pulsating waveform.

The transformer 103 is a high-frequency transformer of which a workingfrequency ranges from 50 KHz to 2 MHz. The high-frequency transformer isconfigured to couple the modulated voltage with the first pulsatingwaveform to the secondary side so as to output via the secondarywinding. In embodiments of the present disclosure, with thehigh-frequency transformer, a characteristic of a small size compared tothe low-frequency transformer (also known as an industrial frequencytransformer, mainly used in the frequency of mains supply such asalternating current of 50 Hz or 60 Hz) may be exploited to realizeminiaturization of the power adapter 1.

In an embodiment of the present disclosure, as illustrated in FIG. 1B,the power adapter 1 may also adopt a forward switching power supply. Indetail, the transformer 103 includes a first winding, a second windingand a third winding. A dotted device of the first winding is coupled toa second output end of the first rectification unit 101 via a backwarddiode. A non-dotted device of the first winding is coupled to a dotteddevice of the second winding and then coupled to a first output end ofthe first rectification unit 101. A non-dotted device of the secondwinding is coupled to the switch unit 102. The third winding is coupledto the second rectification unit 104. The backward diode is configuredto realize reverse peak clipping. An induced potential generated by thefirst winding may perform amplitude limiting on a reverse potential viathe backward diode and return limited energy to an output of the firstrectification unit 101, so as to charge the output of the firstrectification unit 101. Moreover, a magnetic field generated by currentflowing through the first winding may demagnetize a core of thetransformer, so as to return magnetic field intensity in the core of thetransformer to an initial state. The transformer 103 is configured tooutput the voltage with the second pulsating waveform according to themodulated voltage with the first pulsating waveform.

According to an embodiment of the present disclosure, as illustrated inFIG. 1C, the above-mentioned power adapter 1 may adopt a push-pullswitching power supply. In detail, the transformer includes a firstwinding, a second winding, a third winding and a fourth winding. Adotted device of the first winding is coupled to the switch unit. Anon-dotted device of the first winding is coupled to a dotted device ofthe second winding and then coupled to the first output end of the firstrectification unit. A non-dotted device of the second winding is coupledto the switch unit. A non-dotted device of the third winding is coupledto a dotted device of the fourth winding. The transformer is configuredto output the voltage with the second pulsating waveform according tothe modulated voltage with the first pulsating waveform.

As illustrated in FIG. 1C, the switch unit 102 includes a first MOStransistor Q1 and a second MOS transistor Q2. The transformer 103includes a first winding, a second winding, a third winding and a fourthwinding. A dotted device of the first winding is coupled to a drain ofthe first MOS transistor Q1 in the switch unit 102. A non-dotted deviceof the first winding is coupled to a dotted device of the secondwinding. A node between the non-dotted device of the first winding andthe dotted device of the second winding is coupled to the first outputend of the first rectification unit 101. A non-dotted device of thesecond winding is coupled to a drain of the second MOS transistor Q2 inthe switch unit 102. A source of the first MOS transistor Q1 is coupledto a source of the second MOS transistor Q2 and then coupled to thesecond output end of the first rectification unit 101. A dotted deviceof the third winding is coupled to a first input end of the secondrectification unit 104. A non-dotted device of the third winding iscoupled to a dotted device of the fourth winding. A node between thenon-dotted device of the third winding and the dotted device of thefourth winding is grounded. A non-dotted device of the fourth winding iscoupled to a second input end of the second rectification unit 104.

As illustrated in FIG. 1C, the first input end of the secondrectification unit 104 is coupled to the dotted device of the thirdwinding, and the second input end of the second rectification unit 104is coupled to the non-dotted device of the fourth winding. The secondrectification unit 104 is configured to rectify the voltage with thesecond pulsating waveform and to output the voltage with the thirdpulsating waveform. The second rectification unit 104 may include twodiodes. An anode of one diode is coupled to the dotted device of thethird winding. An anode of another diode is coupled to a non-dotteddevice of the fourth winding. A cathode of one diode is coupled to thatof the other diode.

According to an embodiment of the present disclosure, as illustrated inFIG. 1D, the above-mentioned power adapter 1 may also adopt ahalf-bridge switching power supply. In detail, the switch unit 102includes a first MOS transistor Q1, a second MOS transistor Q2, a firstcapacitor C1 and a second capacitor C2. The first capacitor C1 and thesecond capacitor C2 are coupled in series, and then coupled in parallelto the output ends of the first rectification unit 101. The first MOStransistor Q1 and the second MOS transistor Q2 are coupled in series,and then coupled in parallel to the output ends of the firstrectification unit 101. The transformer 103 includes a first winding, asecond winding and a third winding. A dotted device of the first windingis coupled to a node between the first capacitor C1 and the secondcapacitor C2 coupled in series. A non-dotted device of the first windingis coupled to a node between the first MOS transistor Q1 and the secondMOS transistor Q2 coupled in series. A dotted device of the secondwinding is coupled to the first input end of the second rectificationunit 104. A non-dotted device of the second winding is coupled to adotted device of the third winding, and then grounded. A non-dotteddevice of the third winding is coupled to the second input end of thesecond rectification unit 104. The transformer 103 is configured tooutput the voltage with the second pulsating waveform according to themodulated voltage with the first pulsating waveform.

According to an embodiment of the present disclosure, as illustrated inFIG. 1E, the above-mentioned power adapter 1 may also adopt afull-bridge switching power supply. In detail, the switch unit 102includes a first MOS transistor Q1, a second MOS transistor Q2, a thirdMOS transistor Q3 and a fourth MOS transistor Q4. The third MOStransistor Q3 and the fourth MOS transistor Q4 are coupled in series andthen coupled in parallel to the output ends of the first rectificationunit 101. The first MOS transistor Q1 and the second MOS transistor Q2are coupled in series and then coupled in parallel to the output ends ofthe first rectification unit 101. The transformer 103 includes a firstwinding, a second winding and a third winding. A dotted device of thefirst winding is coupled to a node between the third MOS transistor Q3and the fourth MOS transistor Q4 coupled in series. A non-dotted deviceof the first winding is coupled to a node between the first MOStransistor Q1 and the second MOS transistor Q2 coupled in series. Adotted device of the second winding is coupled to the first input end ofthe second rectification unit 104. A non-dotted device of the secondwinding is coupled to a dotted device of the third winding, and thengrounded. A non-dotted device of the third winding is coupled to thesecond input end of the second rectification unit 104. The transformer103 is configured to output the voltage with the second pulsatingwaveform according to the modulated voltage with the first pulsatingwaveform.

Therefore, in embodiments of the present disclosure, the above-mentionedpower adapter 1 may adopt any one of the flyback switching power supply,the forward switching power supply, the push-pull switching powersupply, the half-bridge switching power supply and the full-bridgeswitching power supply to output the voltage with the pulsatingwaveform.

Further, as illustrated in FIG. 1A, the second rectification unit 104 iscoupled to the secondary winding of the transformer 103. The secondrectification unit 104 is configured to rectify the voltage with thesecond pulsating waveform and output a voltage with a third pulsatingwaveform. The second rectification unit 104 may consist of a diode, andcan realize a secondary synchronous rectification, such that the thirdpulsating waveform keeps synchronous with a waveform of the modulatedvoltage with the first pulsating waveform. It should be noted that, thethird pulsating waveform keeping synchronous with the waveform of themodulated voltage with the first pulsating waveform means that, a phaseof the third pulsating waveform is consistent with that of the modulatedvoltage with the first pulsating waveform, and a variation trend ofmagnitude of the third pulsating waveform is consistent with that of themodulated voltage with the first pulsating waveform. The first charginginterface 105 is coupled to the second rectification unit 104. Thesampling unit 106 is configured to sample a voltage and/or a currentoutput by the second rectification unit 104 to obtain a voltage samplingvalue and/or a current sampling value. The control unit 107 is coupledto the sampling unit 106 and the switch unit 102 respectively. Thecontrol unit 107 is configured to output the control signal to theswitch unit 102, and to adjust the duty ratio of the control signalaccording to the voltage sampling value and/or the current samplingvalue, such that the voltage with the third pulsating waveform outputtedby the second rectification unit 104 meets a charging requirement.

As illustrated in FIG. 1A, the device 2 includes a second charginginterface 201 and a battery 202. The second charging interface 201 iscoupled to the battery 202. When the second charging interface 201 iscoupled to the first charging interface 105, the second charginginterface 201 is configured to apply the voltage with the thirdpulsating waveform to the battery 202 to realize a charging of thebattery 202.

It should be noted that, the voltage with the third pulsating waveformmeeting the charging requirement means that, the voltage and currentwith the third pulsating waveform need to meet the charging voltage andcharging current when the battery is charged. In other words, thecontrol unit 107 is configured to adjust the duty ratio of the controlsignal (such as a PWM signal) according to a sampled voltage and/orcurrent outputted by the power adapter, so as to adjust the output ofthe second rectification unit 104 in real time and realize a closed-loopadjusting control, such that the voltage with the third pulsatingwaveform meets the charging requirement of the device 2, thus ensuringthe stable and safe charging of the battery 202. In detail, a waveformof a charging voltage outputted to a battery 202 is illustrated in FIG.3 , in which the waveform of the charging voltage is adjusted accordingto the duty ratio of the PWM signal. A waveform of a charging currentoutputted to a battery 202 is illustrated in FIG. 4 , in which thewaveform of the charging current is adjusted according to the duty ratioof the PWM signal.

It can be understood that, when adjusting the duty ratio of the PWMsignal, an adjusting instruction may be generated according to thevoltage sampling value, or according to the current sampling value, oraccording to the voltage sampling value and the current sampling value.

Therefore, in embodiments of the present disclosure, by controlling theswitch unit 102, a PWM chopping modulation can be directly performed onthe voltage with the first pulsating waveform i.e. the steamed-bunshaped waveform after a rectification, and then a modulated voltage issent to the high-frequency transformer and is coupled from the primaryside to the secondary side via the high-frequency transformer, and thenis changed back to the voltage/current with the steamed-bun shapedwaveform after a synchronous rectification. The voltage/current with thesteamed-bun shaped waveform is directly transmitted to the battery so asto realize quick charging to the battery. The magnitude of the voltagewith the steamed-bun shaped waveform may be adjusted according to theduty ratio of the PWM signal, such that the output of the power adaptermay meet the charging requirement of the battery. It can be seen fromthat, the power adapter according to embodiments of the presentdisclosure, without providing electrolytic capacitors at the primaryside and the secondary side, may directly charge the battery via thevoltage with the steamed-bun shaped waveform, such that a size of thepower adapter may be reduced, thus realizing miniaturization of thepower adapter, and decreasing cost greatly.

In an embodiment of the present disclosure, the control unit 107 may bean MCU (micro controller unit), which means that the control unit 107may be a micro-processor integrated with a switch driving controlfunction, a synchronous rectification function, a voltage and currentadjusting control function.

According to an embodiment of the present disclosure, the control unit107 is further configured to adjust a frequency of the control signalaccording to the voltage sampling value and/or the current samplingvalue. That is, the control unit 107 is further configured to control tooutput the PWM signal to the switch unit 102 for a continuous timeperiod, and then to stop outputting for a predetermined time period andthen to restart to output the PWM signal. In this way, the voltageapplied to the battery is intermittent, thus realizing intermittentcharging of the battery, which can avoid a safety risks caused by heatgenerated when the battery is charged continuously and improves thereliability and safety of the charging to the battery.

Under a low temperature condition, since the conductivity of ions andelectrons in a lithium battery decreases, it is prone to intensify thedegree of polarization during a charging process for the lithiumbattery. A continuous charging not only makes this polarization seriousbut also increases a possibility of lithium precipitation, thusaffecting safety performance of the battery. Furthermore, the continuouscharging may accumulate heat generated due to the charging, thus leadingto an increasing of internal temperature of the battery. When thetemperature exceeds a certain value, performance of the battery may belimited, and safety risks may increase.

In embodiments of the present disclosure, by adjusting the frequency ofthe control signal, the power adapter outputs intermittently, whichmeans that a battery resting process is introduced into the chargingprocess, such that the lithium precipitation due to the polarizationduring the continuous charging is reduced and continuous accumulation ofgenerated heat may be avoided to lower the temperature, thus ensuringthe safety and reliability of charging to the battery.

The control signal outputted to the switch unit 102 is illustrated inFIG. 5A, for example. Firstly, the PWM signal is outputted for acontinuous time period, then the output of the PWM signal is stopped fora certain time period, and then the PWM signal is outputted for acontinuous time period again. In this way, the control signal outputtedto the switch unit 102 is intermittent, and the frequency is adjustable.

As illustrated in FIG. 1A, the control unit 107 is coupled to the firstcharging interface 105. The control unit 107 is further configured toobtain status information of the device 2 by performing a communicationwith the device 2 via the first charging interface 105. In this way, thecontrol unit 107 is further configured to adjust the duty ratio of thecontrol signal (such as the PWM signal) according to the statusinformation of the device, the voltage sampling value and/or the currentsampling value.

The status information of the device may include an electric quantity ofthe battery, a temperature of the battery, a voltage of the battery,interface information of the device and information on path impedance ofthe device.

In detail, the first charging interface 105 includes a power wire and adata wire. The power wire is configured to charge the battery. The datawire is configured to communicate with the device. When the secondcharging interface 201 is coupled to the first charging interface 105,communication query instructions may be transmitted by the power adapter1 and the device 2 to each other. A communication connection can beestablished between the power adapter 1 and the device 2 after receivinga corresponding reply instruction. The control unit 107 may obtain thestatus information of the device 2, so as to negotiate with the device 2about a charging mode and charging parameters (such as the chargingcurrent, the charging voltage) and to control the charging process.

The charging mode supported by the power adapter and/or the device mayinclude a second charging mode and a first charging mode. A chargingspeed of the first charging mode is faster than that of the secondcharging mode. For example, a charging current of the first chargingmode is greater than that of the second charging mode. In general, thesecond charging mode may be understood as a charging mode in which arated output voltage is 5V and a rated output current is less than orequal to 2.5 A. In addition, in the second charging mode, D+ and D− inthe data wire of an output port of the power adapter may beshort-circuited. On the contrary, in the first charging mode accordingto embodiments of the present disclosure, the power adapter may realizedata exchange by communicating with the device via D+ and D− in the datawire, i.e., quick charging instructions may be sent by the power adapterand the device to each other. The power adapter sends a quick chargingquery instruction to the device. After receiving a quick charging replyinstruction from the device, the power adapter obtains the statusinformation of the device and enables the first charging mode accordingto the quick charging reply instruction. The charging current in thefirst charging mode may be greater than 2.5 A, for example, may be 4.5 Aor more. The second charging mode is not limited in embodiments of thepresent disclosure. As long as the power adapter supports two chargingmodes, one of which has a charging speed (or current) greater than thatof the other charging mode, the charging mode with a slower chargingspeed may be regarded as the second charging mode. As to the chargingpower, the charging power in the first charging mode may be greater thanor equal to 15 W.

The control unit 107 communicates with the device 2 via the firstcharging interface 105 to determine the charging mode. The charging modeincludes the first charging mode and the second charging mode.

In detail, the power adapter is coupled to the device via a universalserial bus (USB) interface. The USB interface may be a general USBinterface, a micro USB interface or another typed USB interface. A datawire in the USB interface is configured as the data wire in the firstcharging interface, and configured for a bidirectional communicationbetween the power adapter and the device. The data wire may be D+ and/orD− wire in the USB interface. The bidirectional communication may referto an information interaction performed between the power adapter andthe device.

The power adapter performs the bidirectional communication with thedevice via the data wire in the USB interface, so as to determine tocharge the device in the first charging mode.

It should be noted that, during a process that the power adapter and thedevice negotiate whether to charge the device in the first chargingmode, the power adapter may only keep a coupling with the device butdoes not charge the device, or charges the device in the second chargingmode or charges the device with a small current, which is not limitedherein.

The power adapter adjusts a charging current to a charging currentcorresponding to the first charging mode, and charges the device. Afterdetermining to charge the device in the first charging mode, the poweradapter may directly adjust the charging current to the charging currentcorresponding to the first charging mode or may negotiate with thedevice about the charging current of the first charging mode. Forexample, the charging current corresponding to the first charging modemay be determined according to a current electric quantity of thebattery of the device.

In embodiments of the present disclosure, the power adapter does notincrease the output current blindly for quick charging, but needs toperform the bidirectional communication with the device so as tonegotiate whether to adopt the first charging mode. In contrast to therelated art, the safety of quick charging is improved.

As an embodiment, the control unit 107 is configured to send a firstinstruction to the device when performing the bidirectionalcommunication with the device via the data wire of the first charginginterface so as to determine to charge the device in the first chargingmode. The first instruction is configured to query the device whether toenable the first charging mode. The control unit is configured toreceive a reply instruction to the first instruction from the device.The reply instruction to the first instruction is configured to indicatethat the device agrees to enable the first charging mode.

As an embodiment, before the control unit sends the first instruction tothe device, the power adapter is configured to charge the device in thesecond charging mode. The control unit is configured to send the firstinstruction to the device when determining that a charging duration ofthe second charging mode is greater than a predetermined threshold.

It should be understood that, when the power adapter determines that thecharging duration of the second charging mode is greater than thepredetermined threshold, the power adapter may determine that the devicehas identified it as a power adapter, such that the quick charging querycommunication may be enabled.

As an embodiment, after determining that the device has been charged fora predetermined time period with a charging current greater than orequal to a predetermined current threshold, the power adapter isconfigured to send the first instruction to the device.

As an embodiment, the control unit is further configured to control thepower adapter to adjust a charging current to a charging currentcorresponding to the first charging mode by controlling the switch unit.Before the power adapter charges the device with the charging currentcorresponding to the first charging mode, the control unit is configuredto perform the bidirectional communication with the device via the datawire of the first charging interface to determine a charging voltagecorresponding to the first charging mode, and to control the poweradapter to adjust a charging voltage to the charging voltagecorresponding to the first charging mode.

As an embodiment, when the control unit performs the bidirectionalcommunication with the device via the data wire of the first charginginterface to determine the charging voltage corresponding to the firstcharging mode, the control unit is configured to send a secondinstruction to the device. The second instruction is configured to querywhether a current output voltage of the power adapter is suitable forbeing used as the charging voltage corresponding to the first chargingmode. The control unit is configured to receive a reply instruction tothe second instruction sent from the device. The reply instruction tothe second instruction is configured to indicate that the current outputvoltage of the power adapter is suitable, high or low. The control unitis configured to determine the charging voltage corresponding to thefirst charging mode according to the reply instruction to the secondinstruction.

As an embodiment, before controlling the power adapter to adjust thecharging current to the charging current corresponding to the firstcharging mode, the control unit is further configured to perform thebidirectional communication with the device via the data wire of thefirst charging interface to determine the charging current correspondingto the first charging mode.

As an embodiment, when performing the bidirectional communication withthe device via the data wire of the first charging interface todetermine the charging current corresponding to the first charging mode,the control unit is configured to send a third instruction to thedevice. The third instruction is configured to query a maximum chargingcurrent currently supported by the device. The control unit isconfigured to receive a reply instruction to the third instruction sentfrom the device. The reply instruction to the third instruction isconfigured to indicate the maximum charging current currently supportedby the device. The control unit is configured to determine the chargingcurrent corresponding to the first charging mode according to the replyinstruction to the third instruction.

The power adapter may determine the above maximum charging current asthe charging current corresponding to the first charging mode, or mayset the charging current as a charging current less than the maximumcharging current.

As an embodiment, during a process that the power adapter charges thedevice in the first charging mode, the control unit is furtherconfigured to perform the bidirectional communication with the devicevia the data wire of the first charging interface, so as to continuouslyadjust a charging current outputted to the battery from the poweradapter by controlling the switch unit.

The power adapter may query the status information of the devicecontinuously, for example, query the voltage of the battery of thedevice, the electric quantity of the battery, etc., so as to adjust thecharging current continuously.

As an embodiment, when the control unit performs the bidirectionalcommunication with the device via the data wire of the first charginginterface to continuously adjust the charging current outputted to thebattery from the power adapter by controlling the switch unit, thecontrol unit is configured to send a fourth instruction to the device.The fourth instruction is configured to query a current voltage of thebattery in the device. The control unit is configured to receive a replyinstruction to the fourth instruction sent by the device. The replyinstruction to the fourth instruction is configured to indicate thecurrent voltage of the battery in the device. The control unit isconfigured to adjust the charging current outputted to the battery fromthe power adaptor by controlling the switch unit according to thecurrent voltage of the battery.

As an embodiment, the control unit is configured to adjust the chargingcurrent outputted to the battery from the power adapter to a chargingcurrent value corresponding to the current voltage of the battery bycontrolling the switch unit according to the current voltage of thebattery and a predetermined correspondence between battery voltagevalues and charging current values.

In detail, the power adapter may store the correspondence betweenbattery voltage values and charging current values in advance. The poweradapter may also perform the bidirectional communication with the devicevia the data wire of the first charging interface to obtain from thedevice the correspondence between battery voltage values and chargingcurrent values stored in the device.

As an embodiment, during the process that the power adapter charges thedevice in the first charging mode, the control unit is furtherconfigured to determine whether the first charging interface and thesecond charging interface are in poor contact by performing thebidirectional communication with the device via the data wire of thefirst charging interface. When determining that the first charginginterface and the second charging interface are in poor contact, thecontrol unit is configured to control the power adapter to quit thefirst charging mode.

As an embodiment, before determining whether the first charginginterface and the second charging interface are in poor contact, thecontrol unit is further configured to receive from the deviceinformation indicating path impedance of the device. The control unit isconfigured to send a fourth instruction to the device. The fourthinstruction is configured to query a current voltage of the battery inthe device. The control unit is configured to receive a replyinstruction to the fourth instruction sent by the device. The replyinstruction to the fourth instruction is configured to indicate thecurrent voltage of the battery in the device. The control unit isconfigured to determine path impedance from the power adapter to thebattery according to an output voltage of the power adapter and thecurrent voltage of the battery and determines whether the first charginginterface and the second charging interface are in poor contactaccording to the path impedance from the power adapter to the battery,the path impedance of the device, and path impedance of a chargingcircuit between the power adapter and the device.

The device may record the path impedance thereof in advance. Forexample, since the devices in the same type have the same structure, thepath impedance of each device in the same type is set to the same valuewhen configuring factory settings. Similarly, the power adapter mayrecord the path impedance of the charging circuit in advance. When thepower adapter obtains the voltage across two ends of the battery of thedevice, the path impedance of the whole path can be determined accordingto the voltage drop cross two ends of the battery and the current of thepath. When the path impedance of the whole path>the path impedance ofthe device+the path impedance of the charging circuit, or the pathimpedance of the whole path−(the path impedance of the device+the pathimpedance of the charging wire)>an impedance threshold, it can beconsidered that the first charging interface and the second charginginterface are in poor contact.

As an embodiment, before the power adapter quits the first chargingmode, the control unit is further configured to send a fifth instructionto the device. The fifth instruction is configured to indicate that thefirst charging interface and the second charging interface are in poorcontact.

After sending the fifth instruction, the power adapter may quit thefirst charging mode or reset.

The quick charging process according to embodiments of the presentdisclosure has been described from the perspective of the power adapter;in the following, the quick charging process according to embodiments ofthe present disclosure will be described from the perspective of thedevice.

It should be understood that, the interaction between the power adapterand the device, relative characteristics, functions described at thedevice side correspond to descriptions at the power adapter side, thusrepetitive description will be omitted for simplification.

According to an embodiment of the present disclosure, as illustrated inFIG. 13 , the device 2 further includes a charging control switch 203and a controller 204. The charging control switch 203, such as a switchcircuit consisting of an electronic switch element, is coupled betweenthe second charging interface 201 and the battery 202, and is configuredto switch on or off a charging process of the battery 202 under acontrol of the controller 204. In this way, the charging process of thebattery 202 can be controlled at the device side, thus ensuring thesafety and reliability of charging to the battery 202.

As illustrated in FIG. 14 , the device 2 further includes acommunication unit 205. The communication unit 205 is configured toestablish a bidirectional communication between the controller 204 andthe control unit 107 via the second charging interface 201 and the firstcharging interface 105. In other words, the device 2 and the poweradapter 1 can perform the bidirectional communication via the data wirein the USB interface. The device 2 supports the second charging mode andthe first charging mode. The charging current of the first charging modeis greater than that of the second charging mode. The communication unit205 is configured to perform the bidirectional communication with thecontrol unit 107 such that the power adapter 1 determines to charge thedevice 2 in the first charging mode, and the control unit 107 controlsthe power adapter 1 to output according to the charging currentcorresponding to the first charging mode, for charging the battery 202in the device 2.

In embodiments of the present disclosure, the power adapter 1 does notincrease the output current blindly for the quick charging, but needs toperform the bidirectional communication with the device 2 to negotiatewhether to adopt the first charging mode. In contrast to the relatedart, the safety of the quick charging process can be improved.

As an embodiment, the controller is configured to receive the firstinstruction sent by the control unit via the communication unit. Thefirst instruction is configured to query the device whether to enablethe first charging mode. The controller is configured to send a replyinstruction to the first instruction to the control unit via thecommunication unit. The reply instruction to the first instruction isconfigured to indicate that the device agrees to enable the firstcharging mode.

As an embodiment, before the controller receives the first instructionsent by the control unit via the communication unit, the battery in thedevice is charged by the power adapter in the second charging mode. Whenthe control unit determines that a charging duration of the secondcharging mode is greater than a predetermined threshold, the controlunit sends the first instruction to the communication unit in thedevice, and the controller receives the first instruction sent by thecontrol unit via the communication unit.

As an embodiment, before the power adapter outputs according to thecharging current corresponding to the first charging mode for chargingthe battery in the device, the controller is configured to perform thebidirectional communication with the control unit via the communicationunit, such that the power adapter determines the charging voltagecorresponding to the first charging mode.

As an embodiment, the controller is configured to receive a secondinstruction sent by the control unit. The second instruction isconfigured to query whether a current output voltage of the poweradapter is suitable for being used as the charging voltage correspondingto the first charging mode. The controller is configured to send a replyinstruction to the second instruction to the control unit. The replyinstruction to the second instruction is configured to indicate that thecurrent output voltage of the power adapter is suitable, high or low.

As an embodiment, the controller is configured to perform thebidirectional communication with the control unit, such that the poweradapter determines the charging current corresponding to the firstcharging mode.

The controller is configured to receive a third instruction sent by thecontrol unit, in which the third instruction is configured to query amaximum charging current currently supported by the device. Thecontroller is configured to send a reply instruction to the thirdinstruction to the control unit, in which the reply instruction to thethird instruction is configured to indicate the maximum charging currentcurrently supported by the device, such that the power adapterdetermines the charging current corresponding to the first charging modeaccording to the maximum charging current.

As an embodiment, during a process that the power adapter charges thedevice in the first charging mode, the controller is configured toperform the bidirectional communication with the control unit, such thatthe power adapter continuously adjusts a charging current outputted tothe battery.

The controller is configured to receive a fourth instruction sent by thecontrol unit, in which the fourth instruction is configured to query acurrent voltage of the battery in the device. The controller isconfigured to send a reply instruction to the fourth instruction to thecontrol unit, in which the reply instruction to the fourth instructionis configured to indicate the current voltage of the battery in thedevice, such that the power adapter continuously adjusts the chargingcurrent outputted to the battery according to the current voltage of thebattery.

As an embodiment, during the process that the power adapter charges thedevice in the first charging mode, the controller is configured toperform the bidirectional communication with the control unit via acommunication unit, such that the power adapter determines whether thefirst charging interface and the second charging interface are in poorcontact.

The controller receives a fourth instruction sent by the control unit.The fourth instruction is configured to query a current voltage of thebattery in the device. The controller sends a reply instruction to thefourth instruction to the control unit, in which the fourth instructionto the fourth instruction is configured to indicate the current voltageof the battery in the device, such that the control unit determineswhether the first charging interface and the second charging interfaceare in poor contact according to an output voltage of the power adapterand the current voltage of the battery.

As an embodiment, the controller is configured to receive a fifthinstruction sent by the control unit. The fifth instruction isconfigured to indicate that the first charging interface and the secondcharging interface are in poor contact.

In order to initiate and adopt the first charging mode, a quick chargingcommunication procedure may be performed between the power adapter andthe device, for example, quick charging of battery can be achievedthrough one or more handshakes. Referring to FIG. 6 , the quick chargingcommunication procedure according to embodiments of the presentdisclosure and respective stages in the quick charging process will bedescribed in detail. It should be understood that, communication actionsor operations illustrated in FIG. 6 are merely exemplary. Otheroperations or various modifications of respective operations in FIG. 6can be implemented in embodiments of the present disclosure. Inaddition, respective stages in FIG. 6 may be executed in an orderdifferent from that illustrated in FIG. 6 , and it is unnecessary toexecute all the operations illustrated in FIG. 6 . It should be notedthat, a curve in FIG. 6 represents a variation trend of a peak value ora mean value of the charging current, rather than a curve of actualcharging current.

As illustrated in FIG. 6 , the quick charging process may include thefollowing five stages.

Stage 1:

After being coupled to a power supply providing device, the device maydetect a type of the power supply providing device via the data wire D+and D−. When detecting that the power supply providing device is a poweradapter, the device may absorb current greater than a predeterminedcurrent threshold I2, such as 1A. When the power adapter detects thatcurrent outputted by the power adapter is greater than or equal to 12within a predetermined time period (such as a continuous time periodT1), the power adapter determines that the device has completed therecognition of the type of the power supply providing device. The poweradapter initiates a handshake communication between the power adapterand the device, and sends an instruction 1 (corresponding to theabove-mentioned first instruction) to query the device whether to enablethe first charging mode (or flash charging).

When receiving from the device a reply instruction indicating that thedevice disagrees to enable the first charging mode, the power adapterdetects the output current of the power adapter again. When the outputcurrent of the power adapter is still greater than or equal to I2 withina predetermined continuous time period (such as a continuous time periodT1), the power adapter initiates a request again to query the devicewhether to start the first charging model. The above actions in stage 1are repeated, until the device replies that it agrees to enable thefirst charging mode or the output current of the power adapter is nolonger greater than or equal to I2.

After the device agrees to enable the first charging mode, the quickcharging process is initiated, and the quick charging communicationprocedure proceeds to stage 2.

Stage 2:

For the voltage with the steamed-bun shaped waveform outputted by thepower adapter, there may be several levels. The power adapter sends aninstruction 2 (corresponding to the above-mentioned second instruction)to the device to query the device whether the output voltage of thepower adapter matches with the current voltage of the battery (orwhether the output voltage of the power adapter is suitable, i.e.,suitable for the charging voltage in the first charging mode), i.e.,whether the output voltage of the power adapter meets the chargingrequirement.

The device replies that the output voltage of the power adapter ishigher, lower or suitable. When the power adapter receives a feedbackindicating that the output voltage of the power adapter is lower orhigher from the device, the control unit adjusts the output voltage ofthe power adapter by one level by adjusting the duty ratio of the PWMsignal, and sends the instruction 2 to the device again to query thedevice whether the output voltage of the power adapter matches.

The above actions in stage 2 are repeated, until the device replies tothe power adapter that the output voltage of the power adapter is at amatching level. And then the quick charging communication procedureproceeds to stage 3.

Stage 3:

After the power adapter receives the feedback indicating that the outputvoltage of the power adapter matches from the device, the power adaptersends an instruction 3 (corresponding to the above-mentioned thirdinstruction) to the device to query the maximum charging currentcurrently supported by the device. The device returns to the poweradapter the maximum charging current currently supported by itself, andthen the quick charging communication procedure goes into stage 4.

Stage 4:

After receiving a feedback indicating the maximum charging currentcurrently supported by the device from the device, the power adapter mayset an output current reference value. The control unit 107 adjusts theduty ratio of the PWM signal according to the output current referencevalue, such that the output current of the power adapter meets thecharging current requirement of the device, and the quick chargingcommunication procedure proceeds to constant current stage. The constantcurrent stage means that the peak value or mean value of the outputcurrent of the power adapter basically remains unchanged (which meansthat the variation amplitude of the peak value or mean value of theoutput current is very small, for example within a range of 5% of thepeak value or mean value of the output current), namely, the peak valueof the current with the third pulsating waveform keeps constant in eachperiod.

Stage 5:

When the quick charging communication procedure proceeds to the constantcurrent stage, the power adapter sends an instruction 4 (correspondingto the above-mentioned fourth instruction) at intervals to query thecurrent voltage of battery in the device. The device may feedback to thepower adapter the current voltage of the battery, and the power adaptermay determine according to the feedback of the current voltage of thebattery whether the poor USB contact (i.e., the poor contact between thefirst charging interface and the second charging interface) is poor andwhether it is necessary to decrease the charging current value of thedevice. When the power adapter determines that the USB is in poorcontact, the power adapter sends an instruction 5 (corresponding to theabove-mentioned fifth instruction), and then the power adapter is reset,such that the quick charging communication procedure proceeds to stage 1again.

In some embodiments of the present disclosure, in stage 1, when thedevice replies to the instruction 1, data corresponding to theinstruction 1 may carry data (or information) on the path impedance ofthe device. The data on the path impedance of the device may be used instage 5 to determine whether the USB is in poor contact.

In some embodiments of the present disclosure, in stage 2, the timeperiod from when the device agrees to enable the first charging mode towhen the power adapter adjusts the voltage to a suitable value may belimited in a certain range. If the time period exceeds a predeterminedrange, the device may determine that there is an exception request, thusa quick reset is performed.

In some embodiments of the present disclosure, in stage 2, the devicemay give a feedback indicating that the output voltage of the poweradapter is suitable/matches to the power adapter when the output voltageof the power adapter is adjusted to a value higher than the currentvoltage of the battery by ΔV (ΔV is about 200-500 mV). When the devicegives a feedback indicating that the output voltage of the power adapteris not suitable (higher or lower) to the power adapter, the control unit107 adjusts the duty ratio of the PWM signal according to the voltagesampling value, so as to adjust the output voltage of the power adapter.

In some embodiments of the present disclosure, in stage 4, the adjustingspeed of the output current value of the power adapter may be controlledto be in a certain range, thus avoiding an abnormal interruption of thequick charging due to a too fast adjusting speed.

In some embodiments of the present disclosure, in stage 5, the variationamplitude of the output current value of the power adapter may becontrolled to be within 5%, i.e., stage 5 may be regarded as theconstant current stage.

In some embodiments of the present disclosure, in stage 5, the poweradapter monitors the impedance of a charging loop in real time, i.e.,the power adapter monitors the impedance of the whole charging loop bymeasuring the output voltage of the power adapter, the charging currentand the read-out voltage of the battery in the device. When theimpedance of the charging loop>the path impedance of the device+theimpedance of the quick charging data wire, it may be considered that theUSB is in poor contact, and thus a quick charging reset is performed.

In some embodiments of the present disclosure, after the first chargingmode is started, a time interval of communications between the poweradapter and the device may be controlled to be in a certain range, suchthat the quick charging reset can be avoided.

In some embodiments of the present disclosure, the termination of thefirst charging mode (or the quick charging process) may be a recoverabletermination or an unrecoverable termination.

For example, when the device detects that the battery is fully chargedor the USB is in poor contact, the quick charging is stopped and reset,and the quick charging communication procedure proceeds to stage 1. Whenthe device disagrees to enable the first charging mode, the quickcharging communication procedure would not proceed to stage 2, thus thetermination of the quick charging process may be considered as anunrecoverable termination.

For another example, when an exception occurs in the communicationbetween the device and the power adapter, the quick charging is stoppedand reset, and the quick charging communication procedure proceeds tostage 1. After requirements for stage 1 are met, the device agrees toenable the first charging mode to restore the quick charging process,and this termination of the quick charging process may be considered asa recoverable termination.

For another example, when the device detects an exception occurring inthe battery, the quick charging is stopped and reset, and the quickcharging communication procedure proceeds to stage 1. After the quickcharging communication procedure proceeds to stage 1, the devicedisagrees to enable the first charging mode. Till the battery returns tonormal and the requirements for stage 1 are met, the device agrees toenable the quick charging to recover the quick charging process. Thistermination of quick charging process may be considered as a recoverabletermination.

It should be noted that, communication actions or operations illustratedin FIG. 6 are merely exemplary. For example, in stage 1, after thedevice is coupled to the power adapter, the handshake communicationbetween the device and the power adapter may be initiated by the device.In other words, the device sends an instruction 1 to query the poweradapter whether to enable the first charging mode (or flash charging).When receiving a reply instruction indicating that the power adapteragrees to enable the first charging mode from the power adapter, thedevice starts the quick charging process.

It should be noted that, communication actions or operations illustratedin FIG. 6 are merely exemplary. For example, after stage 5, there can bea constant voltage charging stage. In other words, in stage 5, thedevice may feedback the current voltage of the battery in the device tothe power adapter. As the voltage of the battery increases continuously,the charging proceeds to the constant voltage charging stage when thecurrent voltage of the battery reaches a constant voltage chargingvoltage threshold. The control unit 107 adjusts the duty ratio of thePWM signal according to the voltage reference value (i.e., the constantvoltage charging voltage threshold), such that the output voltage of thepower adapter meets the charging voltage requirement of the device,i.e., the output voltage of the power adapter basically changes at aconstant rate. During the constant voltage charging stage, the chargingcurrent decreases gradually. When the current drops to a certainthreshold, the charging is stopped and it is identified that the batteryhas been fully charged. The constant voltage charging refers to that thepeak voltage with the third pulsating waveform basically keeps constant.

It should be noted that, in embodiments of the present disclosure,acquiring output voltage of the power adapter means that the peak valueor mean value of voltage with the third pulsating waveform is acquired.Acquiring output current of the power adapter means that the peak valueor mean value of current with the third pulsating waveform is acquired.

In an embodiment of the present disclosure, as illustrated in FIG. 7A,the power adapter 1 further includes a controllable switch 108 and afiltering unit 109 in series. The controllable switch 108 and thefiltering unit 109 in series are coupled to the first output end of thesecond rectification unit 104. The control unit 107 is furtherconfigured to control the controllable switch 108 to switch on whendetermining the charging mode as the second charging mode, and tocontrol the controllable switch 108 to switch off when determining thecharging mode as the first charging mode. The output end of the secondrectification unit 104 is further coupled to one or more groups of smallcapacitors in parallel, which can not only realize a noise reduction,but also reduce the occurrence of surge phenomenon. The output end ofthe second rectification unit 104 is further coupled to an LC filteringcircuit or π type filtering circuit, so as to filter out pulsatinginterference. As illustrated in FIG. 7B, the output end of the secondrectification unit 104 is coupled to an LC filtering circuit. It shouldbe noted that, all capacitors in the LC filtering circuit or the π typefiltering circuit are small capacitors, which occupy small space.

The filtering unit 109 includes a filtering capacitor, which supports astandard charging of 5V corresponding to the second charging mode. Thecontrollable switch 108 may consist of a semiconductor switch elementsuch as a MOS transistor. When the power adapter charges the battery inthe device in the second charging mode (or called as standard charging),the control unit 107 controls the controllable switch 108 to switch onso as to incorporate the filtering unit 109 into the circuit, such thata filtering can be performed on the output of the second rectificationunit. In this way, the direct charging technology is compatible, i.e.,the direct current is applied to the battery in the device so as torealize direct current charging of the battery. For example, in general,the filtering unit includes an electrolytic capacitor and a commoncapacitor such as a small capacitor supporting standard charging of 5V(for example, a solid-state capacitor) in parallel. Since theelectrolytic capacitor occupies a bigger volume, in order to reduce thesize of the power adapter, the electrolytic capacitor may be removedfrom the power adapter and only one capacitor with low capacitance isleft. When the second charging mode is adopted, a branch where the smallcapacitor is located is switched on, and the current is filtered torealize a stable output with low power for performing a direct currentcharging on the battery. When the first charging mode is adopted, abranch where the small capacitor is located is switched off, and theoutput of the second rectification unit 104 directly apply thevoltage/current with pulsating waveform without filtering to thebattery, so as to realize a quick charging of the battery.

According to an embodiment of the present disclosure, the control unit107 is further configured to obtain the charging current and/or thecharging voltage corresponding to the first charging mode according tothe status information of the device and to adjust the duty ratio of thecontrol signal such as the PWM signal according to the charging currentand/or the charging voltage corresponding to the first charging mode,when determining the charging mode as the first charging mode. In otherwords, when determining the current charging mode as the first chargingmode, the control unit 107 obtains the charging current and/or thecharging voltage corresponding to the first charging mode according tothe obtained status information of the device such as the voltage, theelectric quantity and the temperature of the battery, running parametersof the device and power consumption information of applications runningon the device, and adjusts the duty ratio of the control signalaccording to the obtained charging current and/or the charging voltage,such that the output of the power adapter meets the chargingrequirement, thus realizing the quick charging of the battery.

The status information of the device may include the temperature of thedevice. When the temperature of the battery is greater than a firstpredetermined temperature threshold, or the temperature of the batteryis less than a second predetermined temperature threshold, if thecurrent charging mode is the first charging mode, the first chargingmode is switched to the second charging mode. The first predeterminedtemperature threshold is greater than the second predeterminedtemperature threshold. In other words, when the temperature of thebattery is too low (for example, corresponding to less than the secondpredetermined temperature threshold) or too high (for example,corresponding to greater than the first predetermined temperaturethreshold), it is unsuitable to perform the quick charging, such that itneeds to switch from the first charging mode to the second chargingmode. In embodiments of the present disclosure, the first predeterminedtemperature threshold and the second predetermined temperature thresholdcan be set, or can be written into the storage of the control unit (suchas the MCU of the power adapter) according to actual situations.

In an embodiment of the present disclosure, the control unit 107 isfurther configured to control the switch unit 102 to switch off when thetemperature of the battery is greater than a predeterminedhigh-temperature protection threshold. Namely, when the temperature ofthe battery exceeds the high-temperature protection threshold, thecontrol unit 107 needs to apply a high-temperature protection strategy,such that switch unit 102 is off, such that the power adapter stopscharging the battery, thus realizing the high-temperature protection ofthe battery and improving the safety of charging. The high-temperatureprotection threshold may be different from or the same to the firsttemperature threshold. In an embodiment, the high-temperature protectionthreshold is greater than the first temperature threshold.

In another embodiment of the present disclosure, the controller isfurther configured to obtain the temperature of the battery, and tocontrol the charging control switch to switch off (i.e., the chargingcontrol switch can be switched off at the device side) when thetemperature of the battery is greater than the predeterminedhigh-temperature protection threshold, so as to stop the chargingprocess of the battery and to ensure the safety of charging.

Moreover, in an embodiment of the present disclosure, the control unitis further configured to obtain a temperature of the first charginginterface, and to control the switch unit to switch off when thetemperature of the first charging interface is greater than apredetermined protection temperature. In other words, when thetemperature of the charging interface exceeds a certain temperature, thecontrol unit 107 needs to apply the high-temperature protection strategyto control the switch unit 102 to switch off, such that the poweradapter stops charging the battery, thus realizing the high-temperatureprotection of the battery and improving the safety of charging.

Certainly, in another embodiment of the present disclosure, thecontroller obtains the temperature of the first charging interface byperforming the bidirectional communication with the control unit. Whenthe temperature of the first charging interface is greater than thepredetermined protection temperature, the controller controls thecharging control switch (referring to FIGS. 13 and 14 ) to switch off,i.e., switches off the charging control switch at the device side, so asto stop the charging process of the battery, thus ensuring the safety ofcharging.

In detail, in an embodiment of the present disclosure, as illustrated inFIG. 8 , the power adapter 1 further includes a driving unit 110 such asa MOSFET driver. The driving unit 110 is coupled between the switch unit102 and the control unit 107. The driving unit 110 is configured todrive the switch unit 102 to switch on or off according to the controlsignal. Certainly, it should be noted, in other embodiments of thepresent disclosure, the driving unit 110 may also be integrated in thecontrol unit 107.

Further, as illustrated in FIG. 8 , the power adapter 1 further includesan isolation unit 111. The isolation unit 111 is coupled between thedriving unit 110 and the control unit 107, to prevent high voltages fromaffecting the control unit 107 at the secondary side of the transformer103. The isolation unit 111 may be implemented in an optocouplerisolation manner, or in other isolation manners. By setting theisolation unit 111, the control unit 107 may be disposed at thesecondary side of the power adapter 1 (or the secondary winding side ofthe transformer 103), such that it is convenient to communicate with thedevice 2, and the space design of the power adapter 1 becomes easier andsimpler.

Certainly, it should be understood that, in other embodiments of thepresent disclosure, both the control unit 107 and the driving unit 110can be disposed as the primary side, in this way, the isolation unit 111can be disposed between the control unit 107 and the sampling unit 106,so as to prevent high voltages from affecting the control unit 107 atthe secondary side of the transformer 103.

Further, it should be noted that, in embodiments of the presentdisclosure, when the control unit 107 is disposed at the secondary side,an isolation unit 111 is required, and the isolation unit 111 may beintegrated in the control unit 107. In other words, when the signal istransmitted from the primary side to the secondary side or from thesecondary side to the primary side, an isolation unit is required toprevent high voltages from affecting the control unit 107 at thesecondary side of the transformer 103.

In an embodiment of the present disclosure, as illustrated in FIG. 9 ,the power adapter 1 further includes an auxiliary winding and a powersupply unit 112. The auxiliary winding generates a voltage with a fourthpulsating waveform according to the modulated voltage with the firstpulsating waveform. The power supply unit 112 is coupled to theauxiliary winding.

The power supply unit 112 (for example, including a filtering voltageregulator module, a voltage converting module and the like) isconfigured to convert the voltage with the fourth pulsating waveform andoutput a direct current, and to supply power to the driving unit 110and/or the control unit 107 respectively. The power supply unit 112 mayconsist of a small filtering capacitor, a voltage regulator chip orother elements. The power supply unit 112 may process and convert thevoltage with the fourth pulsating waveform and outputs a direct currentwith a low voltage such as 3.3V, 5V or the like.

In other words, the power supply of the driving unit 110 can be obtainedby performing a voltage conversation on the voltage with the fourthpulsating waveform by the power supply unit 112. When the control unit107 is disposed at the primary side, the power supply of the controlunit 107 can also be obtained by performing a voltage conversation onthe voltage with the fourth pulsating waveform by the power supply unit112. As illustrated in FIG. 9 , when the control unit 107 is disposed atthe primary side, the power supply unit 112 provides two lines of directcurrent outputs, so as to supply power to the driving unit 110 and thecontrol unit 107 respectively. An optocoupler isolation unit 111 isarranged between the control unit 107 and the sampling unit 106 toprevent high voltages from affecting the control unit 107 at thesecondary side of the transformer 103.

When the control unit 107 is disposed at the primary side and integratedwith the driving unit 110, the power supply unit 112 supplies power tothe control unit 107 separately. When the control unit 107 is disposedat the secondary side and the driving unit 110 is disposed at theprimary side, the power supply unit 112 supplies power to the drivingunit 110 separately. The power supply to the control unit 107 isrealized by the secondary side, for example, a power supply unitconverts the voltage with the third pulsating waveform outputted by thesecond rectification unit 104 to a direct current to supply power to thecontrol unit 107.

Moreover, in embodiments of the present disclosure, several smallcapacitors are coupled in parallel to the output end of firstrectification unit 101 for filtering. Or the output end of the firstrectification unit 110 is coupled to an LC filtering circuit.

In another embodiment of the present disclosure, as illustrated in FIG.10 , the power adapter 1 further includes a first voltage detecting unit113. The first voltage detecting unit 113 is coupled to the auxiliarywinding and the control unit 107 respectively. The first voltagedetecting unit 113 is configured to detect the voltage with the fourthripple waveform to generate a voltage detecting value. The control unit107 is further configured to adjust the duty ratio of the control signalaccording to the voltage detecting value.

In other words, the control unit 107 may reflect the voltage outputtedby the second rectification unit 104 according to the voltage outputtedby the secondary winding and detected by the first voltage detectingunit 113, and then adjusts the duty ratio of the control signalaccording to the voltage detecting value, such that the output of thesecond rectification unit 104 meets the charging requirement of thebattery.

In detail, in an embodiment of the present disclosure, as illustrated inFIG. 11 , the sampling unit 106 includes a first current samplingcircuit 1061 and a first voltage sampling circuit 1062. The firstcurrent sampling circuit 1061 is configured to sample the currentoutputted by the second rectification unit 104 so as to obtain thecurrent sampling value. The first voltage sampling circuit 1062 isconfigured to sample the voltage outputted by the second rectificationunit 104 so as to obtain the voltage sampling value.

In an embodiment of the present disclosure, the first current samplingcircuit 1061 can sample the current outputted by the secondrectification unit 104 by sampling a voltage on a resistor (currentdetection resistor) coupled to the first output end of the secondrectification unit 104. The first voltage sampling circuit 1062 cansample the voltage outputted by the second rectification unit 104 bysampling a voltage across the first output end and the second output endof the second rectification unit 104.

Moreover, in an embodiment of the present disclosure, as illustrated inFIG. 11 , the first voltage sampling circuit 1062 includes a peakvoltage sampling and holding unit, a cross-zero sampling unit, a bleederunit and an AD sampling unit. The peak voltage sampling and holding unitis configured to sample and hold a peak voltage of the voltage with thethird pulsating waveform. The cross-zero sampling unit is configured tosample a zero crossing point of the voltage with the third pulsatingwaveform. The bleeder unit is configured to discharge the peak voltagesampling and holding unit at the zero crossing point. The AD samplingunit is configured to sample the peak voltage in the peak voltagesampling and holding unit so as to obtain the voltage sampling value.

By providing with the peak voltage sampling and holding unit, thecross-zero sampling unit, the bleeder unit and the AD sampling unit inthe first voltage sampling circuit 1062, the voltage outputted by thesecond rectification unit 104 may be sampled accurately, and it can beguaranteed that the voltage sampling value keeps synchronous with thevoltage with the first ripple waveform, i.e., the phase and variationtrend of magnitude of the voltage sampling value are consistent withthose of the voltage with the first ripple waveform respectively.

According to an embodiment of the present disclosure, as illustrated inFIG. 12 , the power adapter 1 further includes a second voltage samplingcircuit 114. The second voltage sampling circuit 114 is configured tosample the voltage with the first pulsating waveform. The second voltagesampling circuit 114 is coupled to the control unit 107. When thevoltage value sampled by the second voltage sampling circuit 114 isgreater than a first predetermined voltage value, the control unit 107controls the switch unit 102 to switch on for a predetermined timeperiod, to drain off the surge voltage, spike voltage in the voltagewith the first pulsating waveform.

As illustrated in FIG. 12 , the second voltage sampling circuit 114 canbe coupled to the first output end and the second output end of thefirst rectification unit 101, so as to sample the voltage with the firstpulsating waveform. The control unit 107 determines the voltage valuesampled by the second voltage sampling circuit 114. When the voltagevalue sampled by the second voltage sampling circuit 114 is greater thanthe first predetermined voltage value, it indicates that the poweradapter 1 is suffering the lightning interference and a surge voltageoccurs, and thus it needs to drain off the surge voltage for ensuringthe safety and reliability of charging. The control unit 107 controlsthe switch unit 102 to switch on for a certain time period, to form ableeder path, such that the surge voltage caused by lightning can bedrained off, thus avoiding the interference of the lightning when thepower adapter charges the device, and effectively improving the safetyand reliability of the charging of the device. The first predeterminedvoltage value may be determined according to actual situations.

In an embodiment of the present disclosure, during a process that thepower adapter 1 charges the battery 202 of the device 2, the controlunit 107 is further configured to control the switch unit 102 to switchoff when a voltage value sampled by the sampling unit 106 is greaterthan a second predetermined voltage value. Namely, the control unit 107further determines the magnitude of the voltage value sampled by thesampling unit 106. When the voltage value sampled by the sampling unit106 is greater than the second predetermined voltage value, it indicatesthat the voltage outputted by the power adapter 1 is too high. At thistime, the control unit 107 controls the power adapter 1 to stop chargingthe battery 202 of the device 2 by controlling the switch unit 102 toswitch off. In other words, the control unit 107 can realize theover-voltage protection of the power adapter 1 by controlling the switchunit 102 to switch off, thus ensuring the safety of charging.

Certainly, in an embodiment of the present disclosure, the controller204 obtains the voltage value sampled by the sampling unit 106(referring to FIGS. 13 and 14 ) by performing a bidirectionalcommunication with the control unit 107, and controls the chargingcontrol switch 203 to switch off when the voltage value sampled by thesampling unit 106 is greater than the second predetermined voltagevalue. Namely, the charging control switch 203 is controlled to switchoff at the side of the device 2, so as to stop the charging process ofbattery 202, such that the safety of charging can be ensured.

Further, the control unit 107 is further configured to control theswitch unit 102 to switch off when the current value sampled by thesampling unit 106 is greater than a predetermined current value. Inother words, the control unit 107 further determines the magnitude ofthe current value sampled by the sampling unit 106. When the currentvalue sampled by the sampling unit 106 is greater than the predeterminedcurrent value, it indicates that the current outputted by the poweradapter 1 is too high. At this time, the control unit 107 controls thepower adapter 1 to stop charging the device by controlling the switchunit 102 to switch off. In other words, the control unit 107 realizesthe over-current protection of the power adapter 1 by controlling theswitch unit 102 to switch off, thus ensuring the safety of charging.

Similarly, the controller 204 obtains the current value sampled by thesampling unit 106 (referring to FIGS. 13 and 14 ) by performing thebidirectional communication with the control unit 107, and controls thecharging control switch 203 to switch off when the current value sampledby the sampling unit 106 is greater than the predetermined currentvalue. In other words, the charging control switch 203 is controlled tobe switched off at the side of the device 2, so as to stop the chargingprocess of the battery 202, thus ensuring the safety of charging.

The second predetermined voltage value and the predetermined currentvalue may be set or written into storage of the control unit (forexample, the control unit 107 of the power adaptor 1, such as themicrocontroller unit (MCU)) according to actual situations.

In embodiments of the present disclosure, the device may be a mobiledevice, such as a mobile phone, a mobile power supply such as a powerbank, a multimedia player, a notebook PC, a wearable device or the like.

With the charging system device according to embodiments of the presentdisclosure, the power adapter is controlled to output the voltage withthe third pulsating waveform, and the voltage with the third pulsatingwaveform outputted by the power adapter is directly applied to thebattery of the device, thus realizing quick charging to the batterydirectly by the pulsating output voltage/current. In contrast to theconventional constant voltage and constant current, a magnitude of thepulsating output voltage/current changes periodically, such that alithium precipitation of the lithium battery may be reduced, the servicelife of the battery may be improved, and a probability and intensity ofarc discharge of a contact of a charging interface may be reduced, theservice life of the charging interfaces may be prolonged, and it isbeneficial to reduce polarization effect of the battery, improve acharging speed, and reduce heat of the battery, thus ensuring thereliability and safety of the device during the charging. Moreover,since the power adapter outputs the voltage with the pulsating waveform,it is unnecessary to provide an electrolytic capacitor in the poweradapter, which can not only realize simplification and miniaturizationof the power adapter, but can also decrease cost greatly. Furthermore,during the process of performing the pulsating charging on the batteryof the device through the power adaptor, the length of the valley of theoutputted voltage with the third pulsating waveform is decreased bycontrolling the duty ratio of the control signal through the controlunit, such that a voltage difference between a voltage peak and avoltage valley is reduced, thereby decreasing a fluctuation value of thevoltage of the battery when the battery is charged via the pulsatingcharging. Therefore, it is contributed to sample the peak value of thevoltage of the battery through the battery voltage sampling unit. Thepower adaptor may adjust the charging state in real time according tothe peak value of the voltage of the battery, thereby ensuring thesafety and the reliability of the charging system.

Embodiments of the present disclosure further provide a power adapter.The power adapter includes a first rectification unit, a switch unit, atransformer, a second rectification unit, a first charging interface anda control unit. The first rectification unit is configured to rectify aninput alternating current and output a voltage with a first pulsatingwaveform. The switch unit is configured to modulate the voltage with thefirst pulsating waveform according to a control signal. The transformeris configured to output a voltage with a second pulsating waveformaccording to the modulated voltage with the first pulsating waveform.The second rectification unit is configured to rectify the voltage withthe second pulsating waveform to output a voltage with a third pulsatingwaveform. The first charging interface is coupled to the secondrectification unit, configured to apply the voltage with the thirdpulsating waveform to a battery in a device via a second charginginterface of the device when the first charging interface is coupled tothe second charging interface, in which the second charging interface iscoupled to the battery. The control unit is coupled to the switch unit,and configured to output the control signal to the switch unit and toadjust a duty ratio of the control signal such that the voltage with thethird pulsating waveform meets a charging requirement. During a processthat the power adaptor charges the battery by outputting the voltagewith the third pulsating waveform to the battery, the control unit isconfigured to adjust the duty ratio of the control signal to decrease alength of a valley of the voltage with the third pulsating waveform suchthat a battery voltage sampling unit is configured to sample a peakvalue of a voltage of the battery.

With the power adapter according to embodiments of the presentdisclosure, the voltage with the third pulsating waveform is outputtedvia the first charging interface, and the voltage with the thirdpulsating waveform is directly applied to the battery of the device viathe second charging interface of the device, thus realizing quickcharging to the battery directly by the pulsating outputvoltage/current. In contrast to the conventional constant voltage andconstant current, a magnitude of the pulsating output voltage/currentchanges periodically, such that a lithium precipitation of the lithiumbattery may be reduced, the service life of the battery may be improved,and a probability and intensity of arc discharge of a contact of acharging interface may be reduced, the service life of the charginginterfaces may be prolonged, and it is beneficial to reduce polarizationeffect of the battery, improve a charging speed, and reduce heat of thebattery, thus ensuring the reliability and safety of the device duringthe charging. Moreover, since the voltage with the pulsating waveform isoutput, it is unnecessary to provide an electrolytic capacitor, whichcan not only realize simplification and miniaturization of the poweradapter, but can also decrease cost greatly. Furthermore, during theprocess of performing the pulsating charging on the battery of thedevice through the power adaptor, the length of the valley of theoutputted voltage with the third pulsating waveform is decreased bycontrolling the duty ratio of the control signal through the controlunit, such that a voltage difference between a voltage peak and avoltage valley is reduced, thereby decreasing a fluctuation value of thevoltage of the battery when the battery is charged via the pulsatingcharging. Therefore, it is contributed to sample the peak value of thevoltage of the battery through the battery voltage sampling unit. Thepower adaptor may adjust the charging state in real time according tothe peak value of the voltage of the battery, thereby ensuring thesafety and reliability of the charging system.

FIG. 15 is a flow chart of a charging method according to embodiments ofthe present disclosure. As illustrated in FIG. 15 , the charging methodincludes the followings.

At block S1, when a first charging interface of a power adapter iscoupled to a second charging interface of a device, a firstrectification is performed on alternating current inputted into thepower adapter to output a voltage with a first pulsating waveform.

In other words, a first rectification unit in the power adapterrectifies the inputted alternating current (i.e., the mains supply, suchas alternating current of 220V, 50 Hz or 60 Hz) and outputs the voltage(for example, 100 Hz or 120 Hz) with the first pulsating waveform, suchas a voltage with a steamed-bun shaped waveform.

At block S2, the voltage with the first pulsating waveform is modulatedby a switch unit, and then is converted by a transformer to obtain avoltage with a second pulsating waveform.

The switch unit may consist of a MOS transistor. A PWM control isperformed on the MOS transistor to perform a chopping modulation on thevoltage with the steamed-bun shaped waveform. And then, the modulatedvoltage the first pulsating waveform is coupled to a secondary side bythe transformer, such that the secondary winding outputs the voltagewith the second pulsating waveform.

In an embodiment of the present disclosure, a high-frequency transformeris used for conversion, such that the size of the transformer is small,thus realizing miniaturization of the power adapter with high-power.

At block S3, a second rectification is performed on the voltage with thesecond pulsating waveform to output a voltage with a third pulsatingwaveform. The voltage with the third pulsating waveform may be appliedto a battery of the device via the second charging interface, so as tocharge the battery of the device.

In an embodiment of the present disclosure, the second rectification isperformed by a second rectification unit on the voltage with the secondpulsating waveform. The second rectification unit may consist of diodesor MOS transistors, and can realize a secondary synchronousrectification, such that the third pulsating waveform keeps synchronouswith the waveform of the modulated voltage with the first pulsatingwaveform.

At block S4, a voltage sampling value and/or a current sampling valueare obtained by sampling a voltage and/or current on which the secondrectification is performed.

At block S5, a duty ratio of a control signal is adjusted forcontrolling the switch unit according to the voltage sampling valueand/or the current sampling value, such that the voltage with the thirdpulsating waveform meets a charging requirement.

It should be noted that, the voltage with the third pulsating waveformmeeting the charging requirement means that, the voltage and currentwith the third pulsating waveform need to meet the charging voltage andcharging current when the battery is charged. In other words, the dutyratio of the control signal (such as a PWM signal) is adjusted accordingto the voltage and/or current outputted by the power adapter, so as toadjust the output of the power adapter in real time and realize aclosed-loop adjusting control, such that the voltage with the thirdpulsating waveform meets the charging requirement of the device, thusensuring the stable and safe charging of the battery. In detail, awaveform of a charging voltage outputted to a battery is illustrated inFIG. 3 , in which the waveform of the charging voltage is adjustedaccording to the duty ratio of the PWM signal. A waveform of a chargingcurrent outputted to a battery is illustrated in FIG. 4 , in which thewaveform of the charging current is adjusted according to the duty ratioof the PWM signal.

In an embodiment of the present disclosure, by controlling the switchunit, a PWM chopping modulation can be directly performed on the voltagewith the first pulsating waveform i.e., the steamed-bun shaped waveformafter a full-bridge rectification, and then a modulated voltage is sentto the high-frequency transformer and is coupled from the primary sideto the secondary side via the high-frequency transformer, and then ischanged back to the voltage/current with the steamed-bun shaped waveformafter a synchronous rectification. The voltage/current with thesteamed-bun shaped waveform is directly transmitted to the battery so asto realize quick charging to the battery. The magnitude of the voltagewith the steamed-bun shaped waveform may be adjusted according to theduty ratio of the PWM signal, such that the output of the power adaptermay meet the charging requirement of the battery. It can be seen fromthat, electrolytic capacitors at the primary side and the secondary sidein the power adapter can be removed, and the battery can be directlycharged via the voltage with the steamed-bun shaped waveform, such thata size of the power adapter may be reduced, thus realizingminiaturization of the power adapter, and decreasing cost greatly.

According to an embodiment of the present disclosure, the chargingmethod may include the followings. When a first charging interface of apower adapter is coupled with a second charging interface of the device,a first rectification is performed on an input alternating current tooutput the voltage with the first pulsating waveform. The voltage withthe first pulsating waveform is modulated by controlling the switchunit, and the voltage with the second pulsating waveform is outputted bythe conversion of the transformer. The second rectification is performedon the voltage with the second pulsating waveform to output the voltagewith the third pulsating waveform, and the voltage with the thirdpulsating waveform is applied to the battery of the device via thesecond charging interface. The duty ratio of the control signaloutputted to the switch unit is adjusted such that the voltage with thethird pulsating waveform meets the charging requirement, and during theprocess that the power adaptor charges the battery by outputting thevoltage with the third pulsating waveform to the battery, a troughduration of the third pulsating waveform is decreased by adjusting theduty ratio of the control signal such that the device is configured tosample the peak value of the voltage of the battery.

In other words, during the power adapter charges the battery byoutputting the voltage with the third pulsating waveform, as the batteryis charged with pulsating waveforms, it may not guarantee that the peakvalue of the voltage of the battery is sampled precisely each time bythe battery voltage sampling unit. When the battery is charged with thepulsating waveforms, if the charging current is stopped, the chargingcurrent does not drop to zero immediately, but is decreased slowly. Theshorter the stopped period, the less the change in the charging voltage.Therefore, in embodiments of the present disclosure, the length of thevalley of the voltage with the third pulsating waveform is decreased byadjusting the duty ratio of the control signal, thereby reducing avoltage difference between the peak value and the valley value of thevoltage of the battery. Thus, the fluctuation of the voltage of thebattery is effectively reduced when the battery is charged withpulsating waveforms, which is contributed to sample the peak value ofthe voltage of the battery, thereby ensuring a safety and reliability ofthe charging system.

According to an embodiment of the present disclosure, a frequency of thecontrol signal is adjusted according to a voltage sampling value and/ora current sampling value. That is, the output of the PWM signal to theswitch unit is controlled to maintain for a continuous time period, andthen stop for a predetermined time period and then restart. In this way,the voltage applied to the battery is intermittent, thus realizing theintermittent charging of the battery, which can avoid safety riskscaused by the heat generated when the battery is charged continuouslyand improves the reliability and safety of the charging to the battery.The control signal outputted to the switch unit is illustrated in FIG.5A.

Further, the above charging method further includes: performing acommunication with the device via the first charging interface to obtainstatus information of the device, and adjusting the duty ratio of thecontrol signal according to the status information of the device, thevoltage sampling value and/or current sampling value.

In other words, when the second charging interface is coupled to thefirst charging interface, the power adapter and the device may sendcommunication query instructions to each other, and a communicationconnection can be established between the power adapter and the deviceafter a corresponding reply instruction is received, such that the poweradapter can obtain the status information of the device, negotiates withthe device about the charging mode and the charging parameter (such asthe charging current, the charging voltage) and controls the chargingprocess.

According to an embodiment of the present disclosure, a voltage with afourth pulsating waveform can be generated through a conversion of thetransformer, and the voltage with the fourth pulsating waveform can bedetected to generate a voltage detecting value, and the duty ratio ofthe control signal can be adjusted according to the voltage detectingvalue.

In detail, the transformer can be provided with an auxiliary winding.The auxiliary winding can generate the voltage with the fourth pulsatingwaveform according to the modulated voltage with the first pulsatingwaveform. The output voltage of the power adapter can be reflected bydetecting the voltage with the fourth pulsating waveform, and the dutyratio of the control signal can be adjusted according to the voltagedetecting value, such that the output of the power adapter meets thecharging requirement of the battery.

In an embodiment of the present disclosure, obtaining the voltagesampling value by sampling a voltage on which the second rectificationis performed includes followings. A peak value of the voltage on whichthe second rectification is performed is sampled and hold. A zerocrossing point of the voltage on which the second rectification isperformed is sampled. A peak voltage sampling and holding unitconfigured for sampling and holding the peak voltage at the zerocrossing point is drained off. The peak voltage in the peak voltagesampling and holding unit is sampled so as to obtain the voltagesampling value. In this way, an accurate sampling can be performed onthe voltage outputted by the power adapter, and it can be guaranteedthat the voltage sampling value keeps synchronous with the voltage withthe first pulsating waveform, i.e., the phase and variation trend ofmagnitude of the voltage sampling value are consistent with those of thevoltage with the first pulsating waveform respectively.

Further, in an embodiment of the present disclosure, the above chargingmethod device further includes: sampling the voltage with the firstpulsating waveform, and controlling the switch unit to switch on for apredetermined time period to discharge the surge voltage in the voltagewith the first pulsating waveform when a sampled voltage value isgreater than a first predetermined voltage value.

The voltage with the first pulsating waveform is sampled so as todetermine the sampled voltage value. When the sampled voltage value isgreater than the first predetermined voltage value, it indicates thatthe power adapter is suffering the lightning interference and a surgevoltage occurs, and thus it needs to drain off the surge voltage forensuring the safety and reliability of charging. It is required tocontrol the switch unit to switch on for a certain time period, to forma bleeder path, such that the surge voltage caused by the lightning canbe drained off, thus avoiding interference of the lightning when thepower adapter charges the device, and effectively improving the safetyand reliability of the charging of the device. The first predeterminedvoltage value may be determined according to actual situations.

According an embodiment of the present disclosure, a communication withthe device is performed via the first charging interface to determinethe charging mode. When the charging mode is determined as the firstcharging mode, the charging current and/or charging voltagecorresponding to the first charging mode can be obtained according tothe status information of the device, so as to adjust the duty ratio ofthe control signal according to the charging current and/or chargingvoltage corresponding to the first charging mode. The charging modeincludes the first charging mode and the second charging mode.

In other words, when the current charging mode is determined as thefirst charging mode, the charging current and/or charging voltagecorresponding to the first charging mode can be obtained according tothe status information of the device, such as the voltage, electricquantity, temperature of the battery, running parameters of the deviceand power consumption information of applications running on the deviceor the like. And the duty ratio of the control signal is adjustedaccording to the obtained charging current and/or charging voltage, suchthat the output of the power adapter meets the charging requirement,thus realizing the quick charging of the device.

The status information of the device may include the temperature of thebattery. When the temperature of the battery is greater than a firstpredetermined temperature threshold, or the temperature of the batteryis less than a second predetermined temperature threshold, if thecurrent charging mode is the first charging mode, the first chargingmode is switched to the second charging mode. The first predeterminedtemperature threshold is greater than the second predeterminedtemperature threshold. In other words, when the temperature of thebattery is too low (for example, corresponding to less than the secondpredetermined temperature threshold) or too high (for example,corresponding to greater than the first predetermined temperaturethreshold), it is unsuitable to perform the quick charging, such that itneeds to switch from the first charging mode to the second chargingmode. In embodiments of the present disclosure, the first predeterminedtemperature threshold and the second predetermined temperature thresholdcan be set according to actual situations.

In an embodiment of the present disclosure, the switch unit iscontrolled to switch off when the temperature of the battery is greaterthan a predetermined high-temperature protection threshold. Namely, whenthe temperature of the battery exceeds the high-temperature protectionthreshold, it needs to apply a high-temperature protection strategy tocontrol the switch unit to switch off, such that the power adapter stopscharging the battery, thus realizing the high-temperature protection ofthe battery and improving the safety of charging. The high-temperatureprotection threshold may be different from or the same with the firsttemperature threshold. In an embodiment, the high-temperature protectionthreshold is greater than the first temperature threshold.

In another embodiment of the present disclosure, the device furtherobtains the temperature of the battery, and controls to stop chargingthe battery (for example by controlling a charging control switch toswitch off at the device side) when the temperature of the battery isgreater than the predetermined high-temperature protection threshold, soas to stop the charging process of the battery and to ensure the safetyof charging.

Moreover, in an embodiment of the present disclosure, the chargingmethod further includes: obtaining a temperature of the first charginginterface, and controlling the switch unit to switch off when thetemperature of the first charging interface is greater than apredetermined protection temperature. In other words, when thetemperature of the charging interface exceeds a certain temperature, thecontrol unit needs to apply the high-temperature protection strategy tocontrol the switch unit to switch off, such that the power adapter stopscharging the battery, thus realizing the high-temperature protection ofthe battery and improving the safety of charging.

Certainly, in another embodiment of the present disclosure, the deviceobtains the temperature of the first charging interface by performingthe bidirectional communication with the power adapter via the secondcharging interface. When the temperature of the first charging interfaceis greater than the predetermined protection temperature, the devicecontrols the charging control switch to switch off, i.e., the chargingcontrol switch can be switched off at the device side, so as to stop thecharging process of the battery, thus ensuring the safety of charging.

During a process that the power adapter charges the device, the switchunit is controlled to switch off when the voltage sampling value isgreater than a second predetermined voltage value. Namely, the magnitudeof the voltage sampling value is determined during the process that thepower adapter charges the device. When the voltage sampling value isgreater than the second predetermined voltage value, it indicates thatthe voltage outputted by the power adapter is too high. At this time,the power adapter is controlled to stop charging the device bycontrolling the switch unit to switch off. In other words, theover-voltage protection of the power adapter can be realized bycontrolling the switch unit to switch off, thus ensuring the safety ofcharging.

Certainly, in an embodiment of the present disclosure, the deviceobtains the voltage sampling value by performing a bidirectionalcommunication with the power adapter via the second charging interface,and controls to stop charging the battery when the voltage samplingvalue is greater than the second predetermined voltage value. Namely,the charging control switch is controlled to switch off at the deviceside, so as to stop the charging process, such that the safety ofcharging can be ensured.

In an embodiment of the present disclosure, during the process that thepower adapter charges the device, the switch unit is controlled toswitch off when the current sampling value is greater than apredetermined current value. In other words, during the process that thepower adapter charges the device, the magnitude of the current samplingvalue is determined.

When the current sampling value is greater than the predeterminedcurrent value, it indicates that the current outputted by the poweradapter is too high. At this time, the power adapter is controlled tostop charging the device by controlling the switch unit to switch off.In other words, the over-current protection of the power adapter isrealized by controlling the switch unit to switch off, thus ensuring thesafety of charging.

Similarly, the device obtains the current sampling value by performingthe bidirectional communication with the power adapter via the secondcharging interface, and controls to stop charging the battery when thecurrent sampling value is greater than the predetermined current value.In other words, the charging control switch is controlled to be switchedoff at the device side, such that the charging process of the battery isstopped, thus ensuring the safety of charging.

The second predetermined voltage value and the predetermined currentvalue may be set according to actual situations.

In embodiments of the present disclosure, the status information of thedevice includes the electric quantity of the battery, the temperature ofthe battery, the voltage/current of the battery of the device, interfaceinformation of the device and information on path impedance of thedevice.

In detail, the power adapter can be coupled to the device via auniversal serial bus (USB) interface. The USB interface may be a generalUSB interface, or a micro USB interface. A data wire in the USBinterface is configured as the data wire in the first charginginterface, and configured for the bidirectional communication betweenthe power adapter and the device. The data wire may be D+ and/or D− wirein the USB interface. The bidirectional communication may refer to aninformation interaction performed between the power adapter and thedevice.

The power adapter performs the bidirectional communication with thedevice via the data wire in the USB interface, so as to determine tocharge the device in the first charging mode.

As an embodiment, when the power adapter performs the bidirectionalcommunication with the device via the first charging interface so as todetermine to charge the device in the first charging mode, the poweradapter sends a first instruction to the device. The first instructionis configured to query the device whether to enable the first chargingmode. The power adapter receives a reply instruction to the firstinstruction from the device. The reply instruction to the firstinstruction is configured to indicate that the device agrees to enablethe first charging mode.

As an embodiment, before the power adapter sends the first instructionto the device, the power adapter charges the device in the secondcharging mode. When the power adapter determines that a chargingduration of the second charging mode is greater than a predeterminedthreshold, the power adapter sends the first instruction to the device.

It should be understood that, when the power adapter determines that thecharging duration of the second charging mode is greater than thepredetermined threshold, the power adapter may determine that the devicehas identified it as a power adapter, such that the quick charging querycommunication may be enabled.

As an embodiment, the power adapter is controlled to adjust a chargingcurrent to a charging current corresponding to the first charging modeby controlling the switch unit. Before the power adapter charges thedevice with the charging current corresponding to the first chargingmode, a bidirectional communication is performed with the device via thefirst charging interface to determine a charging voltage correspondingto the first charging mode, and the power adapter is controlled toadjust a charging voltage to the charging voltage corresponding to thefirst charging mode.

As an embodiment, performing the bidirectional communication with thedevice via the first charging interface to determine the chargingvoltage corresponding to the first charging mode includes: sending bythe power adapter a second instruction to the device, receiving by thepower adapter a reply instruction to the second instruction sent fromthe device, and determining by the power adapter the charging voltagecorresponding to the first charging mode according to the replyinstruction to the second instruction. The second instruction isconfigured to query whether a current output voltage of the poweradapter is suitable for being used as the charging voltage correspondingto the first charging mode. The reply instruction to the secondinstruction is configured to indicate that the current output voltage ofthe power adapter is suitable, high or low.

As an embodiment, before controlling the power adapter to adjust thecharging current to the charging current corresponding to the firstcharging mode, the charging current corresponding to the first chargingmode is determined by performing the bidirectional communication withthe device via the first charging interface.

As an embodiment, determining the charging current corresponding to thefirst charging mode by performing the bidirectional communication withthe device via the first charging interface includes: sending by thepower adapter a third instruction to the device, receiving by the poweradapter a reply instruction to the third instruction sent from thedevice and determining by the power adapter the charging currentcorresponding to the first charging mode according to the replyinstruction to the third instruction. The third instruction isconfigured to query a maximum charging current currently supported bythe device. The reply instruction to the third instruction is configuredto indicate the maximum charging current currently supported by thedevice.

The power adapter may determine the above maximum charging current asthe charging current corresponding to the first charging mode, or mayset the charging current as a charging current less than the maximumcharging current.

As an embodiment, during the process that the power adapter charges thedevice in the first charging mode, the bidirectional communication isperformed with the device via the first charging interface, so as tocontinuously adjust a charging current outputted to the battery from thepower adapter by controlling the switch unit.

The power adapter may query the status information of the devicecontinuously, so as to adjust the charging current continuously, forexample, query the voltage of the battery of the device, the electricquantity of the battery, etc.

As an embodiment, performing the bidirectional communication with thedevice via the first charging interface to continuously adjust thecharging current outputted to the battery from the power adapter bycontrolling the switch unit includes: sending by the power adapter afourth instruction to the device, receiving by the power adapter a replyinstruction to the fourth instruction sent by the device, and adjustingthe charging current by controlling the switch unit according to thecurrent voltage of the battery. The fourth instruction is configured toquery a current voltage of the battery in the device. The replyinstruction to the fourth instruction is configured to indicate thecurrent voltage of the battery in the device.

As an embodiment, adjusting the charging current by controlling theswitch unit according to the current voltage of the battery includes:adjusting the charging current outputted to the battery from the poweradapter to a charging current value corresponding to the current voltageof the battery by controlling the switch unit according to the currentvoltage of the battery and a predetermined correspondence betweenbattery voltage values and charging current values.

In detail, the power adapter may store the correspondence betweenbattery voltage values and charging current values in advance.

As an embodiment, during the process that the power adapter charges thedevice in the first charging mode, it is determined whether the firstcharging interface and the second charging interface are in poor contactby performing the bidirectional communication with the device via thefirst charging interface. When it is determined that the first charginginterface and the second charging interface are in poor contact, thepower adapter is controlled to quit the first charging mode.

As an embodiment, before determining whether the first charginginterface and the second charging interface are in poor contact, thepower adapter receives information indicating path impedance of thedevice from the device. The power adapter sends a fourth instruction tothe device. The fourth instruction is configured to query a currentvoltage of the battery in the device. The power adapter receives a replyinstruction to the fourth instruction sent by the device. The replyinstruction to the fourth instruction is configured to indicate thecurrent voltage of the battery in the device. The power adapterdetermines path impedance from the power adapter to the batteryaccording to an output voltage of the power adapter and the currentvoltage of the battery and determines whether the first charginginterface and the second charging interface are in poor contactaccording to the path impedance from the power adapter to the battery,the path impedance of the device, and path impedance of a charging wirebetween the power adapter and the device.

As an embodiment, before the power adapter is controlled to quit thefirst charging mode, a fifth instruction is sent to the device. Thefifth instruction is configured to indicate that the first charginginterface and the second charging interface are in poor contact.

After sending the fifth instruction, the power adapter may quit thefirst charging mode or reset.

The quick charging process according to embodiments of the presentdisclosure has been described from the perspective of the power adapter;hereinafter, the quick charging process according to embodiments of thepresent disclosure will be described from the perspective of the devicein the following.

In embodiments of the present disclosure, the device supports the secondcharging mode and the first charging mode. The charging current of thefirst charging mode is greater than that of the second charging mode.The device performs the bidirectional communication with the poweradapter via the second charging interface such that the power adapterdetermines to charge the device in the first charging mode. The poweradapter outputs according to a charging current corresponding to thefirst charging mode, for charging the battery in the device.

As an embodiment, performing by the device the bidirectionalcommunication with the power adapter via the second charging interfacesuch that the power adapter determines to charge the device in the firstcharging mode includes: receiving by the device the first instructionsent by the power adapter, in which the first instruction is configuredto query the device whether to enable the first charging mode; sendingby the device a reply instruction to the first instruction to the poweradapter. The reply instruction to the first instruction is configured toindicate that the device agrees to enable the first charging mode.

As an embodiment, before the device receives the first instruction sentby the power adapter, the battery in the device is charged by the poweradapter in the second charging mode. When the power adapter determinesthat a charging duration of the second charging mode is greater than apredetermined threshold, the device receives the first instruction sentby the power adapter.

As an embodiment, before the power adapter outputs according to thecharging current corresponding to the first charging mode for chargingthe battery in the device, the device performs the bidirectionalcommunication with the power adapter via the second charging interface,such that the power adapter determines the charging voltagecorresponding to the first charging mode.

As an embodiment, performing by the device the bidirectionalcommunication with the power adapter via the second charging interfacesuch that the power adapter determines the charging voltagecorresponding to the first charging mode includes: receiving by thedevice a second instruction sent by the power adapter, and sending bythe device a reply instruction to the second instruction to the poweradapter. The second instruction is configured to query whether a currentoutput voltage of the power adapter is suitable for being used as thecharging voltage corresponding to the first charging mode. The replyinstruction to the second instruction is configured to indicate that thecurrent output voltage of the power adapter is suitable, high or low.

As an embodiment, before the device receives the charging currentcorresponding to the first charging mode from the power adapter forcharging the battery in the device, the device performs thebidirectional communication with the power adapter via the secondcharging interface, such that the power adapter determines the chargingcurrent corresponding to the first charging mode.

Performing by the device the bidirectional communication with the poweradapter via the second charging interface such that the power adapterdetermines the charging current corresponding to the first charging modeincludes: receiving by the device a third instruction sent by the poweradapter, in which the third instruction is configured to query a maximumcharging current currently supported by the device; sending by thedevice a reply instruction to the third instruction to the poweradapter, in which the reply instruction to the third instruction isconfigured to indicate the maximum charging current currently supportedby the device, such that the power adapter determines the chargingcurrent corresponding to the first charging mode according to themaximum charging current.

As an embodiment, during a process that the power adapter charges thedevice in the first charging mode, the device performs the bidirectionalcommunication with the power adapter via the second charging interface,such that the power adapter continuously adjusts a charging currentoutputted to the battery.

Performing by the device the bidirectional communication with the poweradapter via the second charging interface such that the power adaptercontinuously adjusts a charging current outputted to the batteryincludes: receiving by the device a fourth instruction sent by the poweradapter, in which the fourth instruction is configured to query acurrent voltage of the battery in the device; sending by the device areply instruction to the fourth instruction to the power adapter, inwhich the reply instruction to the fourth instruction is configured toindicate the current voltage of the battery in the device, such that thepower adapter continuously adjusts the charging current outputted to thebattery according to the current voltage of the battery.

As an embodiment, during the process that the power adapter charges thedevice in the first charging mode, the device performs the bidirectionalcommunication with the control unit, such that the power adapterdetermines whether the first charging interface and the second charginginterface are in poor contact.

Performing by the device the bidirectional communication with the poweradapter, such that the power adapter determines whether the firstcharging interface and the second charging interface are in poor contactincludes: receiving by the device a fourth instruction sent by the poweradapter, in which the fourth instruction is configured to query acurrent voltage of the battery in the device; sending by the device areply instruction to the fourth instruction to the power adapter, inwhich the reply instruction to the fourth instruction is configured toindicate the current voltage of the battery in the device, such that thepower adapter determines whether the first charging interface and thesecond charging interface are in poor contact according to an outputvoltage of the power adapter and the current voltage of the battery.

As an embodiment, the device receives a fifth instruction sent by thepower adapter. The fifth instruction is configured to indicate that thefirst charging interface and the second charging interface are in poorcontact.

In order to initiate and adopt the first charging mode, the poweradapter may perform a quick charging communication procedure with thedevice, for example, by one or more handshakes, so as to realize thequick charging of battery. Referring to FIG. 6 , the quick chargingcommunication procedure according to embodiments of the presentdisclosure and respective stages in the quick charging process will bedescribed in detail. It should be understood that, communication actionsor operations illustrated in FIG. 6 are merely exemplary. Otheroperations or various modifications of respective operations in FIG. 6can be implemented in embodiments of the present disclosure. Inaddition, respective stages in FIG. 6 may be executed in an orderdifferent from that illustrated in FIG. 6 , and it is unnecessary toexecute all the operations illustrated in FIG. 6 . It should be notedthat, a curve in FIG. 6 represents a variation trend of a peak value ora mean value of the charging current, rather than a curve of actualcharging current.

In conclusion, with the charging method according to embodiments of thepresent disclosure, the power adapter is controlled to output thevoltage with the third pulsating waveform which meets the chargingrequirement, and the voltage with the third pulsating waveform outputtedby the power adapter is directly applied to the battery of the device,thus realizing quick charging to the battery directly by the pulsatingoutput voltage/current. In contrast to the conventional constant voltageand constant current, a magnitude of the pulsating outputvoltage/current changes periodically, such that a lithium precipitationof the lithium battery may be reduced, the service life of the batterymay be improved, and a probability and intensity of arc discharge of acontact of a charging interface may be reduced, the service life of thecharging interfaces may be prolonged, and it is beneficial to reducepolarization effect of the battery, improve a charging speed, and reduceheat of the battery, thus ensuring the reliability and safety of thedevice during the charging. Moreover, since the power adapter outputsthe voltage with the pulsating waveform, it is unnecessary to provide anelectrolytic capacitor in the power adapter, which can not only realizesimplification and miniaturization of the power adapter, but can alsodecrease cost greatly. Furthermore, during the process of performing thepulsating charging on the battery of the device through the poweradaptor, the length of the valley of the outputted voltage with thethird pulsating waveform is decreased by controlling the duty ratio ofthe control signal through the control unit, such that a voltagedifference between a voltage peak and a voltage valley is reduced,thereby decreasing a fluctuation value of the voltage of the batterywhen the battery is charged via the pulsating charging. Therefore, it iscontributed to sample the peak value of the voltage of the batterythrough the battery voltage sampling unit. The power adaptor may adjustthe charging state in real time according to the peak value of voltageof the battery, thereby ensuring the safety and reliability of thecharging system.

In at least one embodiment of the present disclosure, part or allstructure (hardware and software) of the adapter can be integrated intothe device. Integrated structure of the adapter and the device can becalled as the charging system of the present disclosure, or called as adevice.

In the specification of the present disclosure, it is to be understoodthat terms such as “central,” “longitudinal,” “lateral,” “length,”“width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,”“right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,”“clockwise,” “counterclockwise,” “axial,” “radial,” and “circumference”refer to the orientations and location relations which are theorientations and location relations illustrated in the drawings, and fordescribing the present disclosure and for describing in simple, andwhich are not intended to indicate or imply that the device or theelements are disposed to locate at the specific directions or arestructured and performed in the specific directions, which could not tobe understood to the limitation of the present disclosure.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent disclosure, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, theterms “mounted,” “connected,” “coupled,” “fixed” and the like are usedbroadly, and may be, for example, fixed connections, detachableconnections, or integral connections; may also be mechanical orelectrical connections; may also be direct connections or indirectconnections via intervening structures; may also be inner communicationsof two elements, which can be understood by those skilled in the artaccording to specific situations.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” “one embodiment”, “another example,” “an example,” “aspecific example,” or “some examples,” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example,” “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Those skilled in the art may be aware that, in combination with theexamples described in the embodiments disclosed in this specification,units and algorithm steps can be implemented by electronic hardware, ora combination of computer software and electronic hardware. In order toclearly illustrate interchangeability of the hardware and software,components and steps of each example are already described in thedescription according to the function commonalities. Whether thefunctions are executed by hardware or software depends on particularapplications and design constraint conditions of the technicalsolutions. Persons skilled in the art may use different methods toimplement the described functions for each particular application, butit should not be considered that the implementation goes beyond thescope of the present disclosure.

Those skilled in the art may be aware that, with respect to the workingprocess of the system, the device and the unit, reference is made to thepart of description of the method embodiment for simple and convenience,which are described herein.

In embodiments of the present disclosure, it should be understood that,the disclosed system, device and method may be implemented in other way.For example, embodiments of the described device are merely exemplary.The partition of units is merely a logical function partitioning. Theremay be other partitioning ways in practice. For example, several unitsor components may be integrated into another system, or some featuresmay be ignored or not implemented. Further, the coupling between eachother or directly coupling or communication connection may beimplemented via some interfaces. The indirect coupling or communicationconnection may be implemented in an electrical, mechanical or othermanner.

In embodiments of the present disclosure, it should be understood that,the units illustrated as separate components can be or not be separatedphysically, and components described as units can be or not be physicalunits, i.e., can be located at one place, or can be distributed ontomultiple network units. It is possible to select some or all of theunits according to actual needs, for realizing the objective ofembodiments of the present disclosure.

In addition, each functional unit in the present disclosure may beintegrated in one progressing module, or each functional unit exists asan independent unit, or two or more functional units may be integratedin one module.

If the integrated module is embodied in software and sold or used as anindependent product, it can be stored in the computer readable storagemedium. Based on this, the technical solution of the present disclosureor a part making a contribution to the related art or a part of thetechnical solution may be embodied in a manner of software product. Thecomputer software produce is stored in a storage medium, including someinstructions for causing one computer device (such as a personal PC, aserver, or a network device etc.) to execute all or some of steps of themethod according to embodiments of the present disclosure. Theabove-mentioned storage medium may be a medium able to store programcodes, such as, USB flash disk, mobile hard disk drive (mobile HDD),read-only memory (ROM), random-access memory (RAM), a magnetic tape, afloppy disc, an optical data storage device, and the like.

Although explanatory embodiments have been illustrated and described, itwould be appreciated by those skilled in the art that the aboveembodiments cannot be construed to limit the present disclosure, andchanges, alternatives, and modifications can be made in the embodimentswithout departing from spirit, principles and scope of the presentdisclosure.

What is claimed is:
 1. A power adapter, comprising: a firstrectification unit, without an electrolytic capacitor provided after thefirst rectification unit, configured to rectify an input alternatingcurrent and output a voltage with a first pulsating waveform; a switchunit, configured to modulate the voltage with the first pulsatingwaveform according to a control signal; a transformer, configured tooutput a voltage with a second pulsating waveform according to themodulated voltage with the first pulsating waveform; a secondrectification unit, configured to rectify the voltage with the secondpulsating waveform to output a voltage with a third pulsating waveform,wherein the voltage with the third pulsating waveform is configured tobe applied to a battery in a device for charging the battery of thedevice; a first charging interface, coupled to the second rectificationunit, configured to apply the voltage with the third pulsating waveformto the battery via a second charging interface of the device when thefirst charging interface is coupled to the second charging interface, inwhich the second charging interface is coupled to the battery, and thefirst charging interface comprises: a power wire, configured to chargethe battery, and a data wire, configured to communicate with the device;a control unit, coupled to the switch unit, and configured to output thecontrol signal to the switch unit and to adjust a duty ratio of thecontrol signal such that the voltage with the third pulsating waveformmeets a charging requirement of the device, and during a process thatthe power adaptor charges the battery by outputting the voltage with thethird pulsating waveform to the battery, the control unit is furtherconfigured to adjust the duty ratio of the control signal to decrease atime length of a valley of the voltage with the third pulsating waveformunder a case that a peak value of a voltage of the battery is sampled,wherein, the power adapter is configured to charge the device in asecond charging mode, and the control unit is configured to send a firstinstruction to the device when determining that a charging duration ofthe second charging mode is greater than a predetermined threshold, inwhich, a charging speed of the first charging mode being faster thanthat of the second charging mode, the first instruction is configured toquery the device whether to enable the first charging mode, and whendetermining that the charging duration of the second charging mode isgreater than the predetermined threshold, the power adapter determinesthat the device has identified the power adapter, such that the firstcharging mode is enabled; and the control unit is configured to receivea reply instruction to the first instruction from the device, in whichthe reply instruction to the first instruction is configured to indicatethat the device agrees to enable the first charging mode.
 2. The poweradapter according to claim 1, wherein the control unit is furtherconfigured to control the power adapter to adjust a charging current toa charging current corresponding to the first charging mode bycontrolling the switch unit, and before the power adapter charges thedevice with the charging current corresponding to the first chargingmode, the control unit is configured to perform the bidirectionalcommunication with the device via the data wire of the first charginginterface to determine a charging voltage corresponding to the firstcharging mode, and to control the power adapter to adjust a chargingvoltage to the charging voltage corresponding to the first chargingmode.
 3. The power adapter according to claim 2, wherein when performingthe bidirectional communication with the device via the data wire of thefirst charging interface to determine the charging voltage correspondingto the first charging mode, the control unit is configured to send asecond instruction to the device, in which the second instruction isconfigured to query whether a current output voltage of the poweradapter is suitable for being used as the charging voltage correspondingto the first charging mode; the control unit is configured to receive areply instruction to the second instruction sent from the device, inwhich the reply instruction to the second instruction is configured toindicate that the current output voltage of the power adapter issuitable, high or low; and the control unit is configured to determinethe charging voltage corresponding to the first charging mode accordingto the reply instruction to the second instruction.
 4. The power adapteraccording to claim 3, wherein, before controlling the power adapter toadjust the charging current to the charging current corresponding to thefirst charging mode, the control unit is further configured to performthe bidirectional communication with the device via the data wire of thefirst charging interface to determine the charging current correspondingto the first charging mode.
 5. The power adapter according to claim 4,wherein, when performing the bidirectional communication with the devicevia the data wire of the first charging interface to determines thecharging current corresponding to the first charging mode, the controlunit is configured to send a third instruction to the device, in whichthe third instruction is configured to query a maximum charging currentcurrently supported by the device; the control unit is configured toreceive a reply instruction to the third instruction sent from thedevice, in which the reply instruction to the third instruction isconfigured to indicate the maximum charging current currently supportedby the device; and the control unit is configured to determine thecharging current corresponding to the first charging mode according tothe reply instruction to the third instruction.
 6. The power adapteraccording to claim 5, wherein during a process that the power adaptercharges the device in the first charging mode, the control unit isfurther configured to perform the bidirectional communication with thedevice via the data wire of the first charging interface, so as tocontinuously adjust a charging current outputted to the battery from thepower adapter by controlling the switch unit.
 7. The power adapteraccording to claim 6, wherein, when performing the bidirectionalcommunication with the device via the data wire of the first charginginterface to continuously adjust the charging current outputted to thebattery from the power adapter by controlling the switch unit, thecontrol unit is configured to send a fourth instruction to the device,in which the fourth instruction is configured to query a current voltageof the battery in the device; the control unit is configured to receivea reply instruction to the fourth instruction sent by the device, inwhich the reply instruction to the fourth instruction is configured toindicate the current voltage of the battery in the device; and thecontrol unit is configured to adjust the charging current by controllingthe switch unit according to the current voltage of the battery.
 8. Thepower adapter according to claim 7, wherein the control unit isconfigured to adjust the charging current outputted to the battery fromthe power adapter to a charging current value corresponding to thecurrent voltage of the battery by controlling the switch unit accordingto the current voltage of the battery and a predetermined correspondencebetween battery voltage values and charging current values.
 9. The poweradapter according to claim 6, wherein, during the process that the poweradapter charges the device in the first charging mode, the control unitis further configured to determine whether the first charging interfaceand the second charging interface are in poor contact by performing thebidirectional communication with the device via the data wire of thefirst charging interface, wherein, when determining that the firstcharging interface and the second charging interface are in poorcontact, the control unit is configured to control the power adapter toquit the first charging mode.
 10. The power adapter according to claim9, wherein, before determining whether the first charging interface andthe second charging interface are in poor contact, the control unit isfurther configured to receive information indicating path impedance ofthe device from the device, wherein the control unit is configured tosend a fourth instruction to the device, in which the fourth instructionis configured to query a current voltage of the battery in the device;the control unit is configured to receive a reply instruction to thefourth instruction sent by the device, in which the reply instruction tothe fourth instruction is configured to indicate the current voltage ofthe battery in the device; the control unit is configured to determinepath impedance from the power adapter to the battery according to anoutput voltage of the power adapter and the current voltage of thebattery; and the control unit is configured to determine whether thefirst charging interface and the second charging interface are in poorcontact according to the path impedance from the power adapter to thebattery, the path impedance of the device, and path impedance of acharging circuit between the power adapter and the device.
 11. The poweradapter according to claim 10, wherein, before the power adapter quitsthe first charging mode, the control unit is further configured to senda fifth instruction to the device, in which the fifth instruction isconfigured to indicate that the first charging interface and the secondcharging interface are in poor contact.
 12. A charging method,comprising: performing a first rectification on an input alternatingcurrent to output a voltage with a first pulsating waveform withoutpassing an electrolytic capacitor; modulating the voltage with the firstpulsating waveform; outputting a voltage with a second pulsatingwaveform according to the modulated voltage with the first pulsatingwaveform; performing a second rectification on the voltage with thesecond pulsating waveform to output a voltage with a third pulsatingwaveform; applying the voltage with the third pulsating waveform to abattery via a first charging interface; adjusting a duty ratio of acontrol signal for modulating the voltage with the first pulsatingwaveform such that the voltage with the third pulsating waveform meets acharging requirement; during a process that the power adaptor chargesthe battery by outputting the voltage with the third pulsating waveformto the battery, decreasing a time length of a valley of the voltage withthe third pulsating waveform by adjusting the duty ratio of the controlsignal for modulating the voltage with the first pulsating waveformunder a case that a peak value of a voltage of the battery is sampled,charging the device in a second charging mode; sending a firstinstruction to the device when determining that a charging duration ofthe second charging mode is greater than a predetermined threshold, inwhich, a charging speed of the first charging mode being faster thanthat of the second charging mode, the first instruction is configured toquery the device whether to enable the first charging mode, and whendetermining that the charging duration of the second charging mode isgreater than the predetermined threshold, the power adapter determinesthat the device has identified the power adapter, such that the firstcharging mode is enabled; and receiving a reply instruction to the firstinstruction from the device, in which the reply instruction to the firstinstruction is configured to indicate that the device agrees to enablethe first charging mode.
 13. The charging method according to claim 12,further comprising: when determining the charging mode as the firstcharging mode, obtaining a charging current and/or a charging voltagecorresponding to the first charging mode according to status informationof the device, so as to adjust the duty ratio of the control signalaccording to the charging current and/or the charging voltagecorresponding to the first charging mode.
 14. The charging methodaccording to claim 12, wherein the device performs a bidirectionalcommunication with the power adapter via the second charging interface,such that power adapter determines to charge the device in the firstcharging mode, in which the power adapter outputs according to thecharging current corresponding to the first charging mode, for chargingthe battery in the device.
 15. The charging method according to claim12, wherein modulating the voltage with the first pulsating waveformcomprises: modulating the voltage with the first pulsating waveform bycontrolling a switch unit, outputting a voltage with a second pulsatingwaveform according to the modulated voltage with the first pulsatingwaveform comprises: applying the modulated voltage with the firstpulsating waveform to a primary side of a transformer; and outputtingthe voltage with the second pulsating waveform at a secondary of thetransformer.